Early Childhood Parent Handout week 5

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CHAPTER 11 PHYSICAL DEVELOPMENT IN MIDDLE CHILDHOOD

Playing with Mum and Dad in the Pool

Ohmmar Coates, 9 years, New Zealand

Aided by gains in strength, flexibility, and agility, children at a community pool dive, swim, and toss beach balls. Chapter 11 takes up the diverse physical attainments of middle childhood and their close connection with other domains of development.

Reprinted with permission from The International Museum of Children’s Art, Oslo, Norway

WHAT’S AHEAD IN CHAPTER 11

11.1 Body Growth

Worldwide Variations in Body Size • Secular Trends in Physical Growth • Skeletal Growth • Brain Development

11.2 Health Issues

Nutrition • Overweight and Obesity • Vision and Hearing • Bedwetting • Illnesses • Unintentional Injuries

■ Social Issues: Health: Family Stressors and Childhood Obesity

11.3 Health Education

11.4 Motor Development and Play

Gross-Motor Development • Fine-Motor Development • Individual Differences in Motor Skills • Games with Rules • Adult-Organized Youth Sports • Shadows of Our Evolutionary Past • Physical Education

■ Social Issues: Education: School Recess—A Time to Play, a Time to Learn

I’m on my way, Mom!” hollered 10-year-old Joey as he stuffed the last bite of toast into his mouth, slung his book bag over his shoulder, dashed out the door, jumped on his bike, and headed down the street for school. Joey’s 8-year-old sister Lizzie followed, pedaling furiously until she caught up with Joey.

“They’re branching out,” Rena, the children’s mother and one of my colleagues at the university, commented to me over lunch that day as she described the children’s expanding activities and relationships. Homework, household chores, soccer teams, music lessons, scouting, and friends at school and in the neighborhood were all part of the children’s routine. “It seems the basics are all there; I don’t have to monitor Joey and Lizzie so constantly anymore. Being a parent is still challenging, but it’s more a matter of refinements—helping them become independent, competent, and productive individuals.”

Joey and Lizzie have entered middle childhood—the years from 6 to 11. Around the world, children of this age are assigned new responsibilities. For children in industrialized nations, middle childhood is often called the “school years” because its onset is marked by the start of formal schooling. In village and tribal cultures, the school may be a field or a jungle. But universally, mature members of society guide children of this age period toward real-world tasks that increasingly resemble those they will perform as adults.

This chapter focuses on physical growth in middle childhood—changes less spectacular than those of earlier years. By age 6, the brain has reached 90 percent of its adult weight, and the body continues to grow slowly. In this way, nature gives school-age children the mental powers to master challenging tasks as well as added time—before reaching physical maturity—to acquire the knowledge and skills essential for life in a complex social world.

We begin by reviewing typical growth trends and special health concerns. Then we turn to rapid gains in motor abilities, which support practical everyday activities, athletic skills, and participation in organized games. We will see that each of these attainments is affected by and also contributes to cognitive, emotional, and social development. Our discussion will echo a familiar theme—that all domains are interrelated. ■

11.1 BODY GROWTH

11.1a Describe changes in body size, proportions, and skeletal maturity during middle childhood.

11.1b Describe brain development in middle childhood.

Physical growth during the school years continues at the slow, regular pace of early childhood. At age 6, the average North American child weighs about 45 pounds and is 3½ feet tall. Over the next few years, children will add about 2 to 3 inches in height and 5 pounds in weight each year (see Figure 11.1 on page 406). Between ages 6 and 8, girls are slightly shorter and lighter than boys. By age 9, this trend reverses. Already, Rena noticed, Lizzie was starting to catch up with Joey in physical size as she approached the dramatic adolescent growth spurt, which occurs two years earlier in girls than in boys.

Because the lower portion of the body is growing fastest, Joey and Lizzie appeared longer-legged than they had in early childhood. They grew out of their jeans more quickly than their jackets and frequently needed larger shoes. As in early childhood, girls have slightly more body fat and boys more muscle. After age 8, girls begin accumulating fat at a faster rate, and they will add even more during adolescence (Hauspie & Roelants, 2012).

Figure 11.1 Body growth during middle childhood. Mai and Henry continue the slow, regular pattern of growth they showed in early childhood. Around age 9, girls begin to grow at a faster rate than boys as the adolescent growth spurt draws near.

Photos of mai: © LAURA DWIGHT PHOTOGRAPHY. PHOTOS OF HENRY: ChrisSteer/Getty Images; klaus tiedge/Getty Images; fotostorm/Getty Images

11.1.1 Worldwide Variations in Body Size

Glance into any elementary school classroom, and you will see wide individual differences in body growth. Diversity in physical size is especially apparent when we travel to different nations. Worldwide, a 9-inch gap separates the shortest and tallest 8-year-olds. The shortest children are found among populations in parts of South America, Asia, the Pacific Islands, and parts of Africa, and the tallest among populations in Australia, North America, northern and central Europe, and, again, Africa (Meredith, 1978; Ruff, 2002). These findings remind us that growth norms (age-related averages for height and weight) must be applied cautiously, especially in countries with high immigration rates and many ethnic minorities.

What accounts for these large differences in physical size? Both heredity and environment are involved. Body size sometimes reflects evolutionary adaptations to a particular climate. Long, lean physiques are typical in hot, tropical regions and short, stocky ones in cold, Arctic areas (Katzmarzyk & Leonard, 1998; Stulp & Barrett, 2016).

Body size sometimes results from evolutionary adaptations to a particular climate. These boys live near the equator on Kenya’s tropical coast. Their long, lean physiques permit their bodies to cool easily.

Also, children who grow tallest usually live in developed countries, where food is plentiful and infectious diseases are largely controlled. Physically small children tend to live in less developed regions, where poverty, hunger, inadequate health care, and disease are common (Karra, Subramanian, & Fink, 2017). When families move from poor to wealthy nations, their children not only grow taller but also change to a longer-legged body shape. (Recall that during childhood, the legs are growing fastest.) For example, U.S.-born school-age children of immigrant Guatemalan Mayan parents are, on average, 4½ inches taller, with legs nearly 3 inches longer, than their agemates in Guatemalan Mayan villages (Bogin & Varela-Silva, 2010; Bogin, Hermanussen, & Scheffler, 2018).

11.1.2 Secular Trends in Physical Growth

In industrialized nations, height has been increasing for 150 years (Fudvoye & Parent, 2017). This secular trend in physical growth—systematic change from one generation to the next in body size and in the timing of the attainment of growth milestones—appears in the first two years, expands during childhood and early adolescence, and then pulls back as mature body size is reached. The pattern suggests that the larger size of today’s children is mostly due to a faster rate of physical development.

Although varying considerably in physical size, these fourth graders are taller than previous generations were at the same age. Improved health and nutrition account for this secular trend.

Once again, improved nutrition and health are largely responsible for these growth gains. As developing nations make socioeconomic progress, they also show secular gains (Ji & Chen, 2008). Secular increases are smaller for low-income children, who have poorer diets and are more likely to suffer from growth-stunting illnesses. And in regions with widespread poverty, famine, and disease, either no secular change or a secular decrease in body size has occurred (Bogin, 2013). In most industrialized nations, the secular gain in height has slowed in recent decades. But as we will see later, overweight and obesity have reached epic proportions.

11.1.3 Skeletal Growth

During middle childhood, the bones of the body lengthen and broaden. However, ligaments are not yet firmly attached to bones. This, combined with increasing muscle strength, gives children unusual flexibility of movement. School-age children often seem like “physical contortionists,” turning cartwheels and doing splits and handstands. As their bodies become stronger, many children experience a greater desire for physical exercise. Early evening or nighttime “growing pains”—stiffness and aches in the legs—are common (Lehman & Carl, 2017). These subside as bones strengthen to accommodate increased physical activity and as muscles adapt to an enlarging skeleton.

Between ages 6 and 12, all 20 primary teeth are lost and replaced by permanent ones, with girls losing their teeth slightly earlier than boys. The first teeth to go are the lower and then upper front teeth, giving many first and second graders a “toothless” smile. For a while, the permanent teeth seem much too large. Gradually, growth of the facial bones, especially those of the jaw and chin, causes the child’s face to lengthen and the mouth to widen, accommodating the newly erupting teeth.

Care of the teeth is essential during the school years because dental health affects the child’s appearance, speech, and ability to chew properly. Parents need to remind children to brush their teeth thoroughly, and most children need help with flossing until about 9 years of age. More than 50 percent of U.S. school-age children have at least some tooth decay. Low-SES children have especially high levels, with one-fourth having at least one untreated decayed tooth (Centers for Disease Control and Prevention, 2019a). As decay progresses, children experience pain, embarrassment at damaged teeth, distraction from play and learning, and school absences due to dental-related illnesses.

Malocclusion, a condition in which the upper and lower teeth do not meet properly, occurs in one-third of school-age children. In about 14 percent of cases, serious difficulties in biting and chewing result. Malocclusion can be caused by thumb sucking after permanent teeth erupt. School-age children who continue to engage in the habit may require gentle but persistent encouragement to give it up (Garde et al., 2014). A more frequent cause of malocclusion is crowding of permanent teeth. In some children, this problem clears up as the jaw grows. Others need braces, a common sight by the end of elementary school.

11.1.4 Brain Development

The weight of the brain increases by only 10 percent during middle childhood and adolescence. Nevertheless, considerable growth occurs in certain brain structures. Using fMRI, researchers can detect the volume of two general types of brain tissue: white matter, consisting largely of myelinated nerve fibers, and gray matter, consisting mostly of neurons and their connective fibers. White matter rises steadily throughout childhood and adolescence, especially in the prefrontal cortex (responsible for complex thought), in the parietal lobes (supporting spatial abilities), and in the corpus callosum (leading to more efficient communication between the two cortical hemispheres) (Genc et al., 2018; Giedd et al., 2009; Smit et al., 2012). Because interconnectivity among distant regions of the cerebral cortex increases, the prefrontal cortex becomes a more effective “executive”—coordinating the integrated functioning of various areas.

As children acquire more complex abilities, stimulated neurons increase in synaptic connections, and their neural fibers become more elaborate and myelinated. As a result, gray matter peaks in middle childhood and then declines as synaptic pruning (reduction of unused synapses) and death of surrounding neurons proceed (Markant & Thomas, 2013; Silk & Wood, 2011). Recall from Chapter 5 that about 50 percent of synapses are pruned during childhood and adolescence. Pruning and accompanying reorganization and selection of brain circuits lead to more optimized functioning of specific brain regions and, thus, to more effective information processing. In particular, children gain in executive function, including sustained attention, inhibition, working memory capacity, and organized, flexible thinking.

In middle childhood, the prefrontal cortex becomes a more effective “executive,” coordinating integrated functioning of various brain regions. These changes support the sustained attention and motor coordination this novice skater needs to become proficient at his new sport.

Additional brain development likely takes place at the level of neurotransmitters, chemicals that permit neurons to communicate across synapses (see page 156 in Chapter 5). Over time, neurons become increasingly selective, responding only to certain chemical messages. This change may add to school-age children’s more efficient thinking. Secretions of particular neurotransmitters are related to cognitive performance, social and emotional adjustment, and ability to withstand stress. When neurotransmitters are not present in appropriate balances, children may suffer serious developmental problems, such as inattention and overactivity, emotional disturbance, and epilepsy (an illness involving brain seizures and loss of motor control) (Brooks et al., 2006; Kurian et al., 2011; Weller, Kloos, & Weller, 2006).

Researchers also believe that brain functioning may change in middle childhood because of the influence of hormones. Around age 7 to 8, an increase in androgens (male sex hormones), secreted by the adrenal glands (located on top of the kidneys), occurs in children of both sexes. Androgens will rise further among boys at puberty, when the testes release them in large amounts. Androgens affect brain organization and behavior in many animal species, including humans (Stark & Gibb, 2018). Recall from Chapter 10 that androgens contribute to boys’ higher activity level and physical aggression. They may also promote social dominance and play-fighting, topics we will take up at the end of this chapter.

Ask Yourself

Connect ■ Relate secular trends in physical growth to the concept of cohort effects, discussed on page 41 in Chapter 1.

Apply ■ Joey complained to his mother that it wasn’t fair that his younger sister Lizzie was almost as tall as he was. He worried that he wasn’t growing fast enough. How should Rena respond to Joey’s concern?

Reflect ■ How does your height compare with that of your parents and grandparents when they were your age? Do your observations illustrate secular trends?

11.2 HEALTH ISSUES

11.2a Describe the causes and consequences of serious nutritional problems in middle childhood, giving special attention to obesity.

11.2b List factors that contribute to illness during the school years, and explain how these health challenges can be reduced.

11.2c Describe changes in the occurrence of unintentional injuries during middle childhood, and cite effective interventions.

Children from economically advantaged homes, like Joey and Lizzie, are at their healthiest in middle childhood, full of energy and play. Growth in lung size permits more air to be exchanged with each breath, so children are better able to exercise vigorously without tiring. The cumulative effects of good nutrition, combined with rapid development of the body’s immune system, offer greater protection against disease. In fact, children who spent much time in child-care centers during infancy and early childhood, and therefore experienced more respiratory, ear, and intestinal infections, are sick less often than their agemates later on (Côté et al., 2010; de Hoog et al., 2014; Hullegie et al., 2016). Their increased immunity may grant them a learning advantage because they miss fewer days of school.

Not surprisingly, poverty continues to be a powerful predictor of poor health during middle childhood. Because economically disadvantaged U.S. children often lack health insurance or are publicly insured (see page 76 in Chapter 2), they generally receive a lower standard of care, and many do not have regular access to a doctor. A substantial number also lack such basic necessities as a comfortable home and regular meals.

11.2.1 Nutrition

Children need a well-balanced, plentiful diet to provide energy for successful learning in school and greater physical activity. With their increasing focus on play, friendships, and new activities, many children spend little time at the table. Joey’s hurried breakfast, described at the beginning of this chapter, is a common event in middle childhood. The percentage of U.S. children who eat meals with their families drops sharply between ages 9 and 14. Family dinnertimes have waned in general over the past two decades. Yet eating an evening meal with parents leads to a diet higher in fruits, vegetables, grains, and milk products and lower in soft drinks and fast foods (Hammons & Fiese, 2011; Lopez et al., 2018).

School-age children report that they “feel better” and “focus better” after eating healthy foods and that they feel sluggish, “like a blob,” after eating junk foods. In longitudinal studies of large samples of preschool children, a parent-reported diet high in sugar, salt, fat, and processed foods in early childhood predicted slightly lower IQ at middle childhood, after many factors that might otherwise account for this association were controlled (Leventakou et al., 2016; Northstone et al., 2012). Even mild nutritional deficits can affect cognitive functioning. Among school-age children from middle- to high-SES families, insufficient dietary iron and folate are related to poorer concentration and mental test performance (Arija et al., 2006; Low et al., 2013). Children say that a major barrier to healthy eating is the ready availability of unhealthy options, even in their homes. As one sixth grader commented, “When I get home from school, I think, ‘I’ll have an apple,’ but then I see the bag of chips.”

A mother and daughter prepare a healthy meal together. School-age children need a well-balanced, plentiful diet to provide energy for successful learning and greater physical activity. Even mild nutritional deficits can compromise cognitive functioning.

Recall from Chapter 8 that food familiarity and food preferences are strongly linked: Children like best the foods they have eaten repeatedly in the past. Readily available, healthy between-meal snacks—such as fruit, raw vegetables, and peanut butter—can help meet school-age children’s nutritional needs and increase their liking for healthy foods.

As we saw in earlier chapters, many poverty-stricken children in developing countries and in the United States suffer from serious and prolonged malnutrition. By middle childhood, the effects are apparent in delayed physical growth, impaired motor coordination, inattention, and low IQ. The negative impact of malnutrition on learning and behavior may intensify as children encounter new academic and social challenges at school. First, as in earlier years, growth-stunted school-age children show greater stress reactivity, as indicated by a sharper rise in heart rate and in saliva levels of the stress hormone cortisol (Fernald et al., 2003). Second, a deficient diet alters the production of neurotransmitters in the brain—an effect that can disrupt all aspects of psychological functioning (Goyal, Iannotti, & Raichle, 2018).

Unfortunately, malnutrition that persists from infancy or early childhood into the school years usually results in lasting physical, cognitive, and mental health problems (Liu et al., 2003; Schoenmaker et al., 2015). Government-sponsored supplementary food programs from the early years through adolescence can prevent these effects.

11.2.2 Overweight and Obesity

Mona, a heavy child in Lizzie’s class, often watched from the sidelines during recess. When she did join in games, she was slow and clumsy, the target of unkind comments: “Move it, Tubs!” When Mona’s classmates chose partners for special activities, she was among the last to be selected. Most afternoons, she walked home alone while her schoolmates gathered in groups, talking, laughing, and chasing. At home, Mona sought comfort in high-calorie snacks.

Mona suffers from obesity, a greater-than-20-percent increase over healthy weight, based on body mass index (BMI)—a ratio of weight to height associated with body fat. A BMI above the 85th percentile for a child’s age and sex is considered overweight, and a BMI above the 95th percentile obese. During the past four decades, as adult overweight and obesity has climbed around the globe, so too has childhood overweight and obesity, which has risen ten-fold. The largest population weight gains have occurred in Canada, England, Mexico, and—the leading nation—the United States (see Figure 11.2). Today, 31 percent of U.S. children and adolescents are overweight, more than half of them extremely so: 17 percent are obese (Kann et al., 2018; Ogden et al., 2016). Other industrialized nations, including France, Switzerland, Italy, and South Korea, have seen smaller increases. Yet as Figure 11.2 reveals, without widespread effective intervention, obesity rates even in less-affected countries are expected to continue to rise until at least 2030 (OECD, 2017b).

Obesity rates have also risen in developing countries, where urbanization is shifting populations toward sedentary lifestyles and diets high in meats and energy-dense refined foods (NCD-RisC, 2017). In China, for example, where obesity was nearly nonexistent a generation ago, today 25 percent of children are overweight and 9 percent obese, with two to three times as many boys as girls affected (Jia et al., 2017). In addition to lifestyle changes, a prevailing belief in Chinese culture that excess body fat signifies prosperity and health—carried over from a half-century ago, when famine caused millions of deaths—has contributed to this alarming upsurge. High valuing of sons may induce Chinese parents and grandparents to offer boys especially generous portions of meat, dairy products, and other energy-dense foods that were once scarce but are now widely available.

Figure 11.2 Adult obesity rates (solid lines) and projected further increases (dashed lines) until 2030 in selected industrialized nations. At about 40 percent in 2020 and a projected 47 percent in 2030, the United States outranks all other developed nations in pervasiveness of obesity in the adult population, defined here according to the widely accepted adult standard of a BMI of 30 and above. Even in countries with relatively low rates, obesity is expected to increase until at least 2030. (From OECD, 2017b. Obesity Update. Copyright© 2017 OECD. Adapted by permission.)

As Figure 11.3 reveals, overweight rises with age, and more than half of U.S. overweight school-age children, adolescents, and adults are obese (Centers for Disease Control and Prevention, 2018d; Ogden et al., 2014). Overweight preschoolers are more than five times more likely than their normal-weight peers to be overweight at age 12 (Nader et al., 2006). And most persistently overweight adolescents become overweight or obese adults (Patton et al., 2011; Simmonds et al., 2016).

Cause of Obesity

Childhood obesity is a complex physical disorder with multiple causes. As Table 11.1 reveals, not all children are equally at risk for excessive weight gain. Identical twins are more likely than fraternal twins to resemble each other in BMI, and adopted children tend to resemble their biological parents (Min, Chiu, & Wang, 2013). But heredity accounts for only a tendency to gain weight (Kral & Faith, 2009). Genes influence biological processes responsible for metabolism and sensations of fullness, but these factors are also modified by experience. Growing evidence suggests that excessive food intake, especially of unhealthy foods, induces epigenetic modifications in expression of genes affecting metabolism and weight gain (Lopomo, Burgio, & Migliore, 2016). Alterations in gene expression may underlie the persistence of child and adolescent overweight and obesity into adulthood.

The importance of environment is also evident in the consistent relationship of low SES to overweight and obesity in industrialized nations, especially among ethnic minorities—in the United States, African-American, Hispanic, and Native-American children and adults (Newton, Braithwaite, & Akinyemiju, 2017; Ogden et al., 2016). Factors involved include lack of knowledge about healthy diet; a tendency to buy high-fat, low-cost foods; and family stress, which can prompt overeating.

Figure 11.3 Age-related increase in U.S. overweight and obesity. In early childhood, nearly half of overweight children are obese. From middle childhood on, more than half of overweight individuals are obese. (Based on U.S. Department of Health and Human Services, 2018b.)

As noted in Chapter 5, children who were undernourished in their early years are at risk for later excessive weight gain. Studies in many poverty-stricken regions of the world reveal that growth-stunted children are more likely to be overweight than their nonstunted agemates (de Onis, 2017). In industrialized nations, children whose mothers smoked during pregnancy and who therefore are often born underweight (see Chapter 3) are at elevated risk for later overweight and obesity (Rayfield & Plugge, 2017). A malnourished body protects itself by establishing a low basal metabolism rate, which may endure after nutrition improves. Also, malnutrition may disrupt appetite control centers in the brain, causing the child to overeat when food becomes plentiful.

Table 11.1 Factors Contributing to Childhood Obesity

Factor

Description

Heredity

Obese children are likely to have at least one obese parent, and identical twins are more likely than fraternal twins to share the disorder.

Socioeconomic status

Obesity is more common in low-SES families.

Early growth pattern

Infants who gain weight rapidly are at greater risk for obesity, probably because their parents promote unhealthy eating habits (see Chapter 5).

Family eating habits

When parents purchase high-calorie fast foods, treats, and junk food; use them as rewards; anxiously overfeed; or control their children’s intake, their children are more likely to be obese.

Responsiveness to food cues

Obese children often decide when to eat on the basis of external cues, such as taste, smell, sight, time of day, and food-related words, rather than hunger.

Physical activity

Obese children are less physically active than their normal-weight peers.

Television viewing

Children who spend many hours watching television are more likely to become obese.

Early malnutrition

Early, severe malnutrition that results in growth stunting increases the risk of later obesity.

Nevertheless, in the developing world (unlike industrialized countries), obesity risk tends to be greater for higher-SES families, likely because of greater food availability and reduced activity levels (Ford, Patel, & Narayan, 2017). But as countries improve economically and high-fat, processed foods become plentiful, the burden of obesity shifts from wealthy to low-income families.

Parental feeding practices also contribute to childhood obesity. Overweight children are more likely to eat larger quantities of high-calorie sugary and fatty foods, perhaps because these foods are plentiful in the diets offered by their parents, who also tend to be overweight (Kit, Ogden, & Flegal, 2014). Frequent eating out—which increases parents’ and children’s consumption of high-calorie fast foods—is linked to overweight. And eating out likely plays a major role in the relationship between mothers’ employment hours and elevated BMI among school-age children (Morrissey, Dunifon, & Kalil, 2011). Demanding work schedules reduce the time parents have for healthy meal preparation.

Furthermore, some parents anxiously overfeed, interpreting almost all their child’s discomforts as a desire for food—a practice common among immigrant parents and grandparents who, as children themselves, may have survived periods of food deprivation. Still other parents are overly controlling, restricting when, what, and how much their child eats and worrying about weight gain (Couch et al., 2014; Jansen et al., 2012). In each case, parents undermine children’s ability to regulate their own food intake.

These experiences contribute to obese children’s maladaptive eating habits. They are more responsive than normal-weight individuals to external stimuli associated with food—taste, sight, smell, time of day, and food-related words—and less responsive to internal hunger cues (Temple et al., 2007). And temperament—in particular, weak effortful control and delay of gratification (ability to wait for a reward) during the preschool years—increases the likelihood that children will gain excessive weight in middle childhood (Fiese & Bost, 2016). At the same time, a stressful family life contributes to children’s diminished self-regulatory capacity, amplifying uncontrolled eating (see the Social Issues: Health box on the following page).

Another factor implicated in weight gain is insufficient sleep (Hakim, Kheirandish-Gozal, & Gozall, 2015). A follow-up of more than 2,000 U.S. 3- to 12-year-olds revealed that children who got less nightly sleep were more likely to be overweight five years later (Snell, Adam, & Duncan, 2007). Reduced sleep may increase time available for eating while leaving children too fatigued for physical activity. It also disrupts the brain’s regulation of hunger and metabolism.

Look and Listen

Observe in the check-out area of a supermarket for an hour on a weekend, recording the percentage of families with children whose carts contain large quantities of high-calorie processed foods and soft drinks. In how many of these families are parents and children overweight?

Overweight children are less physically active than their normal-weight peers, and inactivity is both cause and consequence of their excessive weight gain (Kellou et al., 2014). Research reveals that the rise in childhood obesity is due in part to the many hours children devote to screen media. In several longitudinal investigations, more hours per day spent watching TV in childhood and adolescence consistently predicted the likelihood of overweight and obesity in adulthood (Robinson et al., 2017). Many children routinely eat while viewing, and TV and Internet ads encourage unhealthy snacking: The more ads they watch, the greater their consumption of high-calorie snack foods. Screen media may also distract children from attending to sensations of fullness. Children permitted to have a TV in their bedroom—a practice linked to especially high TV viewing—are at even greater risk for weight gain (Borghese et al., 2015; Soos et al., 2014).

Finally, the broader food environment affects the incidence of obesity. The Pima Indians of Arizona, who two decades ago changed from a traditional diet of plant foods to a high-fat, typically American diet, have one of the world’s highest obesity rates. Compared with descendants of their ancestors living in the remote Sierra Madre region of Mexico, the Arizona Pima have body weights 50 percent greater. The Pima have a genetic susceptibility to overweight, but it emerges only under Western dietary conditions (Schulz & Chaudhari, 2015). Other ethnic groups with a hereditary tendency to gain weight are Pacific Islanders, including native Hawaiians and Samoans (Subica et al., 2017). Many now eat an Americanized diet of high-calorie processed foods, and over 80 percent are overweight.

Social Issues: HealthFamily Stressors and Childhood Obesity

In response to chronic stress, many adults and children increase their food consumption—especially foods high in sugar and fat—and gain excessive weight. How can a stressful daily life prompt overeating?

One route is through elevated stress hormones, including cortisol, which signal the body to increase energy expenditure and the brain, in turn, to boost caloric intake (Fiese & Bost, 2016). In a second pathway, chronic stress triggers insulin resistance—a prediabetic condition that frequently induces a raging appetite (Qi & Ding, 2016).

Furthermore, the effort required to manage persistent stress can easily strain self-regulatory capacity, leaving the individual unable to limit excessive eating (Blair, 2010). In several studies, the greater the number of home-life stressors in school-age children’s lives, the poorer their regulation of negative emotion and behavior (Evans et al., 2005; Garasky, 2009). Impaired self-regulation, then, might be a major intervening factor in the link between childhood chronic stress and obesity.

To find out, researchers followed several hundred children from economically disadvantaged families, assessing family stressors and self-regulatory ability at age 9 and change in BMI four years later, at age 13 (Evans, Fuller-Rowell, & Doan, 2012). Number of stressors experienced—including poverty, single-parent household, residential crowding, noise, household clutter, lack of books and play materials, child separation from the family, and exposure to violence—strongly predicted impaired self-regulation, as indicated by children’s delay of gratification. Poor self-regulation, in turn, largely accounted for the relationship between family stressors and gain in BMI over time.

In obesity prevention programs, children given self-regulation training—instructions to “stop and think” in eating situations—show beneficial outcomes in terms of improved eating behaviors and weight loss (Epstein & Anzman-Frasca, 2017; Johnson, 2000). But such training is likely to be fully effective only when stressors in children’s family lives are manageable, not overwhelming.

This 9-year-old, living in shelter housing with her mother, is at high risk for obesity. Home-life stressors, including poverty, single-parenthood, noise, crowding, and clutter, contribute to overeating by impairing children’s capacity for self-regulation.

Consequences of Obesity

Obese children are at risk for lifelong health problems. Symptoms that begin to appear in the early school years—high blood pressure, high cholesterol levels, respiratory abnormalities, insulin resistance, and inflammatory reactions—are powerful predictors of heart disease, circulatory difficulties, type 2 diabetes, gallbladder disease, sleep and digestive disorders, many forms of cancer, and early death. Furthermore, obesity has caused a dramatic rise in cases of diabetes in children, sometimes leading to early, severe complications, including stroke, kidney failure, and circulatory problems that heighten the risk of eventual blindness and leg amputation (Biro & Wien, 2010; Yanovski, 2015). U.S. Pima Indian children who are obese display double the rate of illness-related premature deaths after they reach adulthood as their normal-weight peers.

Unfortunately, physical attractiveness is a powerful predictor of social acceptance. In Western societies, both children and adults rate obese youngsters as unattractive, unhappy, self-doubting, deceitful, lazy, and less successful (Grant, Mizzi, & Anglim, 2016; Harrison, Rowlinson, & Hill, 2016; Di Pasquale & Celsi, 2017). In school, obese children and adolescents are often socially isolated. They report more emotional, social, and school difficulties, including peer teasing, rejection, victimization by bullies, and consequent low self-esteem (Stensland et al., 2015; van Grieken et al., 2013). They also tend to achieve less well than their healthy-weight agemates (Carey et al., 2015).

Because unhappiness and overeating contribute to each other, the child remains overweight. Persistent obesity from childhood into adolescence predicts elevated rates of serious psychological disorders, including severe anxiety and depression, defiance and aggression, and suicidal thoughts and behavior (Lopresti & Drummond, 2013; Puhl & Latner, 2007). Furthermore, overweight girls are more likely to reach puberty early, increasing their risk for early sexual activity and other adjustment problems (Rubin et al., 2009; Stattin & Skoog, 2016). The psychological consequences of obesity combine with continuing discrimination to further impair physical health and reduce life chances of forming close relationships and gaining satisfying employment.

Treating Obesity

Childhood obesity is difficult to treat because it is a family disorder. In Mona’s case, the school nurse suggested that Mona and her obese mother enter a weight-loss program together. But Mona’s mother, unhappily married for many years, had her own reasons for overeating. She rejected this idea, claiming that Mona would eventually decide to lose weight on her own. About 50 to 70 percent of U.S. parents judge their overweight or obese child to have a normal weight (Hansen et al., 2014; McKee et al., 2016). Consistent with these findings, fewer than 20 percent of obese children get any treatment. Although many try to slim down in adolescence, they often go on crash diets that make matters worse. Temporary starvation leads to physical stress, discomfort, and fatigue. Soon the child returns to old eating patterns, and weight rebounds to a higher level. Then, to protect itself, the body burns calories more slowly and becomes more resistant to future weight loss.

The most effective interventions are family-based and focus on changing behaviors (Seburg et al., 2015). In one program, both parent and child revised eating patterns, exercised daily, and reinforced each other with praise and points for progress, which they exchanged for special activities and times together. The more weight parents lost, the more their children lost. Follow-ups after 5 and 10 years showed that children maintained their weight loss more effectively than adults—a finding that underscores the importance of early intervention (Epstein, Roemmich, & Raynor, 2001; Wrotniak et al., 2004). Monitoring dietary intake and physical activity is important. Small wireless sensors that sync with mobile devices, enabling individualized goal-setting and tracking of progress through game-like features, are effective (Calvert, 2015; Seburg et al., 2015). But these interventions work best when parents’ and children’s weight problems are not severe.

This mother and son reinforce each other’s efforts to lose weight and get in shape. The most effective interventions for childhood obesity focus on changing the family’s behaviors, emphasizing fitness and healthy eating.

Children consume one-third of their daily energy intake at school. Therefore, schools can help reduce obesity by serving healthier meals and ensuring regular physical activity. Because obesity is expected to rise further without broad prevention strategies, many U.S. states and cities have passed obesity-reduction legislation. Among measures taken are weight-related school screenings for all children, improved nutrition standards, additional recess time and physical education, and obesity awareness and weight-reduction programs as part of school curricula. Reviews of school-based efforts reveal impressive benefits (Bleich et al., 2018; Shirley et al., 2015). Obesity prevention in schools is more successful in reducing children’s BMIs than programs delivered in other community settings, perhaps because schools are better able to provide long-term, comprehensive intervention.

Look and Listen

Contact your state and local governments to find out about their childhood obesity prevention legislation. Can policies be improved?

Finally, obesity prevention and reduction have become priorities in U.S. federal, state, and local government policies. Among current efforts are the following:

Increased public education about healthy nutrition and physical activity, including limiting time devoted to screen media

Greater access to healthy, affordable foods in low-income neighborhoods, where overweight and obesity are highest

Laws mandating improved labels on foods and menus specifying nutritional content and calories

Improved quality of publicly-supported school breakfasts and lunches

Expanded opportunities for physical activity in schools as well as in communities, by building more parks, recreation centers, and walking and bike paths

11.2.3 Vision and Hearing

The most common vision problem in middle childhood is myopia, or nearsightedness. In most developed nations for which evidence is available, the incidence of myopia increases steadily over middle childhood and adolescence and into adulthood (Rudnicka et al., 2016). Myopia rates, however, vary widely from country to country.

Heritability estimates based on comparisons of twins and other family members reveal a moderate genetic influence (Guggenheim et al., 2015). Worldwide, myopia occurs far more frequently in children and adolescents of East Asian than European ancestry: By high school graduation, 80 percent of Chinese and Japanese children are affected, compared with just under 25 percent of their North American and European counterparts (Rudnicka et al., 2016). Early biological trauma can also induce myopia. School-age children with low birth weights show an especially high rate, believed to result from immaturity of visual structures, slower eye growth, and a greater incidence of eye disease (Molloy et al., 2013).

When parents warn their children not to read in dim light or sit too close to the TV or computer screen, their concern (“You’ll ruin your eyes!”) is well-founded. In diverse cultures, the more time children spend reading, writing, using the computer, and doing other close work, the more likely they are to be myopic. Conversely, in school-age children who spend more time playing outdoors, the incidence of myopia is reduced (Russo et al., 2014). Researchers believe that the increased time children in East Asian countries spend in school, after-school classes, and doing homework contributes to their higher myopia rates (Sun et al., 2018). Myopia is one of the few health conditions to increase with SES, and it has become more prevalent in recent generations. Fortunately, myopia can be overcome easily with corrective lenses.

During middle childhood, the Eustachian tube (canal that runs from the inner ear to the throat) becomes longer, narrower, and more slanted, preventing fluid and bacteria from traveling so easily from the mouth to the ear. As a result, otitis media (middle ear infection), common in infancy and early childhood (see Chapter 8), becomes less frequent. Still, about 3 to 4 percent of the U.S. school-age population, and as many as 20 percent of low-SES children, develop some hearing loss as a result of repeated infections (Aarhus et al., 2015; Ryding et al., 2002). With regular screening for both vision and hearing, defects can be corrected before they lead to serious learning difficulties.

11.2.4 Bedwetting

One Friday afternoon, Terry called Joey to see if he could sleep over, but Joey refused. “I can’t,” said Joey anxiously, without offering an explanation.

“Why not? We can take our sleeping bags out in the backyard. Come on, it’ll be cool!”

“My mom won’t let me,” Joey responded, unconvincingly. “I mean, well, I think we’re busy. We’re doing something tonight.”

“Gosh, Joey, this is the third time you’ve said no. See if I’ll ask you again!” snapped Terry as he hung up the phone.

Joey is one of 15 percent of school-age children in industrialized nations who suffer from nocturnal enuresis, or bedwetting during the night. Twice as many boys as girls are affected. In the overwhelming majority of cases, the problem has biological roots. Heredity is a major contributing factor: Parents with a history of bedwetting are far more likely to have a child with the problem, and identical twins are more likely than fraternal twins to share it (Sarici et al., 2016; von Gontard, Heron, & Joinson, 2011). Most often, enuresis is caused by a failure of muscular responses that inhibit urination or by a hormonal imbalance that permits too much urine to accumulate during the night. Some children also have difficulty awakening to the sensation of a full bladder (Becker, 2013). Punishing a school-age child for wetting makes matters worse.

Difficult temperament in infancy and early childhood elevates risk for later nocturnal enuresis in middle childhood (Joinson et al., 2016; Vasconcelos et al., 2017). The self-regulatory challenges experienced by emotionally reactive young children may contribute directly to urinary incontinence. Alternatively, temperamentally difficult children may be more resistant to parental toilet training, which results in persisting continence problems.

To treat enuresis, doctors often prescribe a synthetic hormone called desmopressin, which reduces the amount of urine produced. Although medication is a short-term solution for children attending camp or visiting a friend’s house, once children stop taking it, they typically begin wetting again. The most effective treatment is a urine alarm that wakes the child at the first sign of dampness and works according to conditioning principles. Success rates of about 75 percent occur after four months of treatment (Mellon & Houts, 2018; Rittig et al., 2014). The few children who relapse achieve dryness after trying the alarm a second time.

Treating nocturnal enuresis has immediate, positive psychological consequences. It leads to gains in restful sleep, parents’ evaluation of their child’s behavior, and children’s self-esteem (Longstaffe, Moffatt, & Whalen, 2000). Although many children outgrow enuresis without intervention, this generally takes years.

11.2.5 Illnesses

Children experience a somewhat higher rate of illness during the first two years of elementary school than later, because of exposure to sick children and an immune system that is still developing. Typically, illness causes children to miss from one to five days of school per year (National Survey of Children’s Health, 2016). Longer absences usually can be traced to a few students with chronic health problems.

About 20 to 25 percent of U.S. children living at home have chronic diseases and conditions (including physical disabilities) (Centers for Disease Control and Prevention, 2017e). By far the most common—accounting for about one-third of childhood chronic illness and the most frequent cause of school absence and childhood hospitalization—is asthma, in which the bronchial tubes (passages that connect the throat and lungs) are highly sensitive (Basinger, 2013). In response to a variety of stimuli, such as cold weather, infection, exercise, allergies, and emotional stress, they fill with mucus and contract, leading to coughing, wheezing, and serious breathing difficulties.

The prevalence of asthma in the United States has increased steadily over the past several decades. It is now at its highest level, with nearly 8 percent of children and adolescents affected. Although heredity contributes to asthma, researchers believe that environmental factors are necessary to spark the illness. Boys, African-American children, and children who were born underweight, whose parents smoke, or who live in poverty are at greatest risk (Centers for Disease Control and Prevention, 2017a). Pollution in urban areas (which triggers allergic reactions), stressful home lives, and lack of access to good health care contribute substantially to the higher rates and greater severity of asthma among low-SES African-American and other poverty-stricken children. Childhood obesity is also linked to asthma (Hampton, 2014; Kranjac et al., 2017). High levels of blood-circulating inflammatory substances associated with body fat and the pressure of excess weight on the chest wall seem to be responsible.

These children, who live in an impoverished community where asthma is common, use a meter to measure the daily concentration of air pollutants. The device will warn them when pollution reaches a level likely to trigger asthma attacks.

About 2 percent of U.S. children have more severe chronic illnesses, such as sickle cell anemia, cystic fibrosis, diabetes, arthritis, cancer, and acquired immune deficiency syndrome (AIDS). Painful medical treatments, physical discomfort, and changes in appearance often disrupt the chronically sick child’s daily life, making it difficult to concentrate in school and separating the child from peers. As the illness worsens, family and child stress increases (Rodriguez, Dunn, & Compas, 2012). For these reasons, chronically ill children are at risk for academic, emotional, and social difficulties. In adolescence, they are more likely than their agemates to suffer from low self-esteem and depression and report more often smoking cigarettes, using illegal drugs, and thinking about and attempting suicide (Champaloux & Young, 2015; Erickson et al., 2005).

A strong link exists between good family functioning and child well-being for chronically ill children, just as it does for physically healthy children (Leeman et al., 2016). Interventions that foster positive family relationships help parent and child cope effectively with the disease and improve adjustment. These include:

Health education, in which parents and children learn about the illness and get training in how to manage it

Home visits by health professionals, who offer counseling and social support to enhance parents’ and children’s strategies for managing the stress of chronic illness

Schools that accommodate children’s special health and education needs

Disease-specific summer camps, which teach children self-help skills and give parents time off from the demands of caring for an ill child

Parent and peer support groups

11.2.6 Unintentional Injuries

As we conclude our discussion of threats to school-age children’s health, let’s turn to the topic of unintentional injuries (discussed in detail in Chapter 8). As Figure 11.4 shows, injury fatalities increase from middle childhood into adolescence, with rates for boys rising considerably above those for girls. Poverty and either rural or urban residence—factors associated with dangerous environments and reduced parental monitoring of children—are also linked to high injury rates (Birken et al., 2006; Ovalle et al., 2016).

Motor vehicle accidents, involving children as passengers or pedestrians, continue to be the leading cause of injury, followed by bicycle accidents (Centers for Disease Control and Prevention, 2019b). School-age children should remain in car booster seats until they reach at least 4 feet 9 inches in height and are between ages 8 and 12, when adult seat belts alone are likely to fit them correctly. Although following these standards reduces serious injury by 45 percent, more than 80 percent of parents fail to do so consistently (Durbin & Hoffman, 2018; Hafner et al., 2017). Pedestrian accidents most often result from midblock dart-outs, and bicycle accidents from disobeying traffic signals and rules. When many stimuli impinge on them at once, young school-age children often fail to think before they act. They need frequent reminders, supervision, and prohibitions against venturing into busy traffic on their own.

Even older school-age children express unrealistic optimism about their likelihood of experiencing commonly occurring injuries—for example, as the result of a bicycle or pedestrian accident. They view themselves as less at risk than their peers (Joshi, Maclean, & Stevens, 2018). Yet a study that tracked routine supervision provided to middle-SES 7- to 10-year-olds at home revealed that the children were unsupervised 35 percent of the time (Morrongiello, Kane, Zdzieborski, 2011). Both nonsupervision and indirect supervision (parent checking on the child intermittently) were associated with increased injuries.

As children range farther from home, safety education related to their widening world becomes important. Effective school- and community-based prevention programs use extensive modeling and rehearsal of safety practices, give children feedback about their performance along with praise and tangible rewards for acquiring safety skills, and provide occasional booster sessions. Targeting specific injury risks (such as traffic safety) rather than many risks at once yields longer-lasting results (Nauta et al., 2014).

One vital safety measure is legally requiring that children wear protective helmets while bicycling, in-line skating, skateboarding, or using scooters. This precaution leads to a 9 percent reduction in head injuries, a leading cause of permanent physical disability and death in school-age children (Karkhaneh et al., 2013). Combining helmet use with preventive education and other community-based prevention strategies is especially effective. In one multifaceted prevention program, children in impoverished urban neighborhoods attended bicycle safety clinics, during which helmets were distributed. They also received traffic safety education in their classrooms and in a simulated traffic environment. In addition, existing playgrounds were improved and new ones constructed to provide expanded off-street play areas, and more community-sponsored, supervised recreational activities were offered (Durkin et al., 1999; Taylor et al., 2018). As a result, motor vehicle and bicycle injuries declined by 36 percent.

Figure 11.4 U.S. rates of injury mortality from middle childhood to adolescence. Injury fatalities increase from middle childhood into adolescence, and the gap between boys and girls expands. Motor vehicle (passenger and pedestrian) accidents are the leading cause, with bicycle injuries next in line. (Based on Centers for Disease Control and Prevention, 2019b.)

Not all children respond to efforts to increase their safety. By middle childhood, the greatest risk-takers tend to be those whose parents do not act as safety-conscious models, rarely supervise their children’s activities, fail to teach safety precautions, or use punitive or inconsistent discipline to enforce rules (Morrongiello, McArthur, & Spence, 2016; Rowe, Maughan, & Goodman, 2004; Tuchfarber, Zins, & Jason, 1997). These child-rearing tactics, as we saw in Chapter 10, spark children’s defiance, reduce their willingness to comply, and actually promote high-risk behavior.

By wearing helmets, these bike riders reduce their risk of head injuries, a leading cause of permanent disability and death in school-age children.

Highly active, impulsive children, many of whom are boys, remain particularly susceptible to injury in middle childhood. Although they have just as much safety knowledge as their peers, they are far less likely to implement it. Parents tend to be particularly lax in intervening in the dangerous behaviors of such children, especially under conditions of persistent marital conflict or other forms of stress (Schwebel et al., 2011, 2012). The greatest challenge for injury-control programs is reaching these children, altering high-risk factors in their families, and reducing the dangers to which they are exposed.

11.3 HEALTH EDUCATION

11.3 Identify steps that parents and teachers can take to encourage good health practices in school-age children.

Psychologists, educators, and pediatricians are intensely interested in finding ways to help school-age children understand their bodies, acquire mature conceptions of health and illness, and develop behaviors that foster health throughout life. Furthermore, the dramatic physical transformations of puberty are not far off. Older school-age children need accurate information about what changes to expect; about reproduction, pregnancy, and childbirth; about the risks of early sexual activity; and about how to avoid unsafe social situations, including online (National Child Traumatic Stress Network, 2009). Middle childhood is an especially important time for fostering healthy lifestyles because of the child’s growing independence, increasing cognitive capacities, and rapidly developing self-concept, which includes a sense of physical well-being.

School-age children can comprehend a wide range of health information—about the structure and functioning of their bodies, about good nutrition, and about the causes and consequences of physical injuries and diseases. When given scientific facts, they build on basic biological concepts acquired during the preschool years, and their understanding advances. For example, a 5-year-old is likely to say, “You get a cold when your friend sneezes and gives you her germs” (Legare, Zhu, & Wellman, 2013). A 10-year-old, in contrast, offers a deeper, more detailed explanation: “You get a cold when your sinuses fill with mucus. Sometimes your lungs do, too, and you get a cough. Colds come from viruses. They get into the bloodstream and make your platelet count go down” (Myant & Williams, 2005).

Without effective teaching, however, school-age children readily generalize their knowledge of familiar health conditions to less familiar ones. As a result, they may conclude that risk factors for colds (getting sneezed on, sharing a Coke) can cause AIDS or that cancer (like a cold) is contagious (González-Rivera & Bauermeister, 2007). Furthermore, supernatural accounts of illness widespread in certain cultures—such as “Maybe his sickness is punishment for bad behavior”—must be gently countered with scientific facts (Raman & Gelman, 2004). Otherwise, these incorrect ideas can lead to unnecessary anxiety about getting a serious disease.

Applying What We Know

Strategies for Fostering Healthy Lifestyles in School-Age Children

Strategy

Description

Increase health-related knowledge and encourage healthy behaviors.

Provide health education that imparts scientific information about health concepts and healthy lifestyles and that includes modeling, role playing, rehearsal, and reinforcement of good health practices.

Involve parents in supporting health education.

Communicate with parents about health education goals in school, encouraging them to extend these efforts at home. Teach parents about unhealthy dietary practices and how to create healthy food environments at home. Promote proper parental supervision by providing information on children’s age-related safety capacities. Inform parents about the importance of educating children about pubertal changes and sexuality.

Provide healthy environments in schools.

Ask school administrators to ensure that school breakfasts and lunches follow widely accepted dietary guidelines. Limit access to vending machines with junk food. Work for daily recess periods in elementary school and mandatory daily physical education at all grade levels. Begin sex education in elementary school, offering information that informs children about and helps them cope with pubertal changes.

Make voluntary screening for risk factors available as part of health education.

Offer periodic measures of height, weight, body mass, blood pressure, and adequacy of diet. Educate children about the meaning of each index, and encourage improvement.

Promote pleasurable physical activity.

Provide opportunities for regular, vigorous physical exercise through activities that de-emphasize competition and that stress skill building and personal and social enjoyment.

Teach children to be critical of media advertising.

Besides teaching children to be skeptical of ads for unhealthy foods on TV and other screen media, reduce such advertising in schools—for example, on sports scoreboards.

Work for safer, healthier community environments for children.

Form community action groups to improve child safety, school nutrition, and play environments, and initiate community programs that foster healthy physical activity.

Nevertheless, most efforts to impart health information to school-age children have little impact on behavior (Tinsley, 2003). Several related reasons underlie this gap between knowledge and practice:

Health is seldom an important goal for children, who feel good most of the time. They are far more concerned about schoolwork, friends, and play.

Children do not yet have an adultlike time perspective that relates past, present, and future. They cannot see the connection between engaging in preventive behaviors now and experiencing later health consequences.

Much health information given to children is contradicted by other sources, such as media advertising and the examples of adults and peers.

Consequently, teaching school-age children health-related facts, though crucial, must be supplemented by other efforts. As we have seen, a powerful means of fostering children’s health is to reduce hazards, such as pollution, an unhealthy diet, and inadequate medical and dental care. At the same time, environments will never be totally free of health risks, so parents and teachers must coach children in good health practices and model and reinforce these behaviors. Refer to Applying What We Know above for ways to foster healthy lifestyles in school-age children.

A visiting doctor discusses biological information about the human body with fifth graders. When school-age children are provided with scientific facts, they gain in understanding of health and illness.

Ask Yourself

Connect ■ Select one of the following health problems of middle childhood: obesity, myopia, bedwetting, asthma, or unintentional injuries. Explain how both genetic and environmental factors contribute to it.

Apply ■ Nine-year-old Talia is afraid to hug and kiss her grandmother, who has cancer. What might explain Talia’s mistaken belief that the same behaviors that cause colds to spread might lead her to catch cancer? What would you do to change her thinking?

Reflect ■ List unintentional injuries that you experienced as a child. Were you injury-prone? Why or why not?

11.4 MOTOR DEVELOPMENT AND PLAY

11.4a Cite major changes in gross- and fine-motor development during middle childhood.

11.4b Describe individual differences in motor performance during middle childhood.

11.4c Describe qualities of children’s play that are evident in middle childhood.

11.4d Identify steps that schools can take to promote physical fitness in middle childhood.

Visit a park on a pleasant weekend afternoon, and watch several preschool and school-age children at play. You will see that gains in body size and muscle strength support improved motor coordination during middle childhood. And greater cognitive and social maturity enables older children to use their new motor skills in more complex ways. A major change in children’s play takes place at this time.

11.4.1 GROSS-MOTOR DEVELOPMENT

During the school years, running, jumping, hopping, and ball skills become more refined. At Joey and Lizzie’s school, I watched during the third to sixth graders’ recess. Children burst into sprints as they raced across the playground, jumped quickly over rotating ropes, engaged in intricate hopscotch patterns, kicked and dribbled soccer balls, batted at balls pitched by their classmates, and balanced adeptly as they walked heel-to-toe across narrow ledges. Table 11.2 summarizes gross-motor achievements between 6 and 12 years of age. These diverse skills reflect gains in four basic motor capacities:

Flexibility. Compared with preschoolers, school-age children are physically more pliable and elastic, a difference evident as they swing bats, kick balls, jump over hurdles, and execute tumbling routines.

Balance. Improved balance supports many athletic skills, including running, hopping, skipping, throwing, kicking, and the rapid changes of direction required in many team sports.

Agility. Quicker and more accurate movements are evident in the fancy footwork of dance and cheerleading and in the forward, backward, and sideways motions used to dodge opponents in tag and soccer.

Force. Older children can throw and kick a ball harder and propel themselves farther off the ground when running and jumping than they could at earlier ages (Haywood & Getchell, 2014).

Along with body growth, more efficient information processing plays a vital role in improved gross-motor performance. Younger children often have difficulty with skills that require rapid responding, such as dribbling and batting. During middle childhood, the capacity to react only to relevant information increases. And steady gains in reaction time occur, including anticipatory responding to repeated visual stimuli, such as a thrown ball in a game of catch or a turning rope in a game of jump rope: Ten-year-olds react twice as quickly as 5-year-olds (Debrabant et al., 2012; Kail, 2003). These differences in speed of reaction have practical implications for physical education. Because 5- to 7-year-olds are seldom successful at batting a thrown ball, T-ball is more appropriate for them than baseball. Similarly, handball, four-square, and kickball should precede instruction in tennis, basketball, and football.

Improved physical flexibility, balance, agility, and force, along with more efficient information processing, promote gains in school-age children’s gross motor skills.

Children’s gross-motor activity not only benefits from but contributes to cognitive development. Physical fitness predicts improved executive function, memory, and academic achievement in middle childhood (Chaddock et al., 2011). Exercise-induced changes in the brain seem to be responsible: Brain-imaging research reveals that structures supporting attentional control and memory are larger, and myelination of neural fibers within them greater, in better-fit than in poorly-fit children (Chaddock et al., 2010a, 2010b; Chaddock-Heyman et al., 2014). Furthermore, children who are physically fit—and those assigned to a yearlong, one-hour-per-day school fitness program—activate these brain structures more effectively while performing executive function tasks (Chaddock et al., 2012; Chaddock-Heyman et al., 2013). Mounting evidence supports the role of vigorous exercise in optimal brain and cognitive functioning in childhood—a relationship that persists throughout the lifespan.

Table 11.2 Changes in Gross-Motor Skills During Middle Childhood

Skill

Developmental Change

Running

Running speed increases from 12 feet per second at age 6 to more than 18 feet per second at age 12.

Other gait variations

Skipping improves. Sideways stepping appears around age 6 and becomes more continuous and fluid with age.

Vertical jump

Height jumped increases from 4 inches at age 6 to 12 inches at age 12.

Standing broad jump

Distance jumped increases from 3 feet at age 6 to more than 5 feet at age 12.

Precision jumping and hopping (on a mat divided into squares)

By age 7, children can accurately jump and hop from square to square, a performance that improves until age 9 and then levels off.

Throwing

Throwing speed, distance, and accuracy increase for both sexes, but much more for boys than for girls. At age 6, a ball thrown by a boy travels 39 feet per second, and one by a girl, 29 feet per second. At age 12, a ball thrown by a boy travels 78 feet per second, and one by a girl, 56 feet per second.

Catching

Ability to catch small balls thrown over greater distances improves with age.

Kicking

Kicking speed and accuracy improve, with boys considerably ahead of girls. At age 6, a ball kicked by a boy travels 21 feet per second, and one by a girl, 13 feet per second. At age 12, a ball kicked by a boy travels 34 feet per second, and one by a girl, 26 feet per second.

Batting

Batting motions become more effective with age, increasing in speed and accuracy and involving the entire body.

Dribbling

Style of hand dribbling gradually changes, from awkward slapping of the ball to continuous, relaxed, even stroking.

Sources: Haywood & Getchell, 2014; Malina & Bouchard, 1991

11.4.2 Fine-Motor Development

Fine-motor development also improves over the school years. On rainy afternoons, Joey and Lizzie experimented with yo-yos, built model airplanes, and wove potholders on small looms. Like many children, they took up musical instruments, which demand considerable fine-motor control.

Gains in fine-motor skill are especially evident in children’s writing and drawing. By age 6, most children can print the alphabet, their first and last names, and the numbers from 1 to 10 with reasonable clarity. Their writing is large, however, because they make strokes using the entire arm rather than just the wrist and fingers. Children usually master uppercase letters first because their horizontal and vertical motions are easier to control than the small curves of the lowercase alphabet. Legibility of writing gradually increases as children produce more accurate letters with uniform height and spacing.

Figure 11.5 Increase in organization, detail, and depth cues in school-age children’s drawings. Compare both drawings to the one by a 5-year-old in Figure 8.6 on page 299. In the drawing by an 8-year-old on the left, notice how all parts are depicted in relation to one another and with greater detail. Integration of depth cues increases dramatically over the school years, as shown in the drawing on the right, by an 11-year-old. Here, depth is indicated by overlapping objects, diagonal placement, and converging lines, as well as by making distant objects smaller than near ones.

Children’s drawings show dramatic gains in organization, detail, and representation of depth during middle childhood. By the end of the preschool years, children can accurately copy many two-dimensional shapes, and they integrate these into their drawings. Some depth cues have also begun to appear, such as making distant objects smaller than near ones (Braine et al., 1993). Yet recall from Chapter 8 that before age 8, children have trouble accurately copying a three-dimensional form, such as a cube or cylinder (see page 299 in Chapter 8). Around 9 to 10 years, the third dimension is clearly evident through overlapping objects, diagonal placement, and converging lines. Furthermore, as Figure 11.5 shows, school-age children not only depict objects in considerable detail but also relate them to one another as part of an organized whole (Case & Okamoto, 1996).

11.4.3 Individual Differences in Motor Skills

As at younger ages, school-age children show marked individual differences in motor capacities that are influenced by both heredity and environment. Body build is influential: Taller, more muscular children excel at many motor tasks. And children whose parents encourage physical exercise tend to enjoy it more and also to be more skilled.

Family income affects children’s access to lessons needed to develop abilities in areas such as ballet, tennis, gymnastics, and instrumental music. For children from low-SES homes, school and community provisions for nurturing athletics and other motor skills by making lessons, equipment, and opportunities for regular practice available and affordable are crucial. When these experiences combine with parental encouragement, many low-SES children become highly skilled.

Sex differences in motor skills that appeared during the preschool years extend into middle childhood and, in some instances, become more pronounced. Girls have an edge in fine-motor skills of handwriting and drawing and in gross-motor capacities that depend on balance and agility, such as hopping and skipping (Haywood & Getchell, 2014). But boys outperform girls on all other skills listed in Table 11.2, especially throwing and kicking.

School-age boys’ genetic advantage in muscle mass is not large enough to account for their gross-motor superiority. Rather, the social environment plays a larger role. Research confirms that parents hold higher expectations for boys’ athletic performance, and children readily absorb these messages. From first through twelfth grades, girls are less positive than boys about the value of sports and their own sports ability—differences explained in part by parental beliefs (Anderson, Hughes, & Fuemmeler, 2009; Fredricks & Eccles, 2002; Noordstar et al., 2016). The more strongly girls believe that females are incompetent at sports (such as hockey or soccer), the lower they judge their own ability and the poorer they actually perform (Belcher et al., 2003; Chalabaev, Sarrazin, & Fontayne, 2009).

Fourth graders gather in their schoolyard for a pick-up game of basketball. School-age children show marked individual differences in motor capacities that are influenced by both heredity and environment.

Tony Tallec / Alamy Stock Photo

Educating parents about the minimal differences between school-age boys’ and girls’ physical capacities and sensitizing them to unfair biases against promotion of girls’ athletic ability may help increase girls’ self-confidence and participation in athletics. Greater emphasis on skill training for girls, along with increased attention to their athletic achievements, is also likely to help. As a positive sign, compared with a generation ago, many more girls now participate in individual and team sports such as gymnastics and soccer, though their involvement continues to lag behind boys’ (Bassett et al., 2015; Kanters et al., 2013; Sabo & Veliz, 2011). Middle childhood is a crucial time to encourage girls’ sports participation because during this period, children start to discover what they are good at and make some definite skill commitments.

11.4.4 Games with Rules

The physical activities of school-age children reflect an important advance in quality of play: Games with rules become common. Children around the world engage in an enormous variety of informally organized games, including variants on popular sports such as soccer, baseball, and basketball. In addition to the best-known childhood games, such as tag, jacks, and hopscotch, children have also invented hundreds of other games, including red rover, statues, leapfrog, kick the can, and prisoner’s base.

Gains in perspective taking—in particular, the ability to understand the roles of several players in a game—permit this transition to rule-oriented games. These play experiences, in turn, contribute greatly to emotional and social development. Child-invented games usually rely on simple physical skills and a sizable element of luck. As a result, they rarely become contests of individual ability. Instead, they permit children to try out different styles of cooperating, competing, winning, and losing with little personal risk. Also, in their efforts to organize a game, children discover why rules are necessary and which ones work well. In fact, they often spend as much time working out the details of how a game should proceed as they do playing the game! As we will see in Chapter 13, these experiences help children form more mature concepts of fairness and justice.

Compared with past generations, school-age children today spend less time engaged in informal outdoor play—a change that reflects parental concern about neighborhood safety as well as competition for children’s time from TV and other screen media. Another factor is the rise in adult-organized sports, such as Little League baseball and soccer and hockey leagues, which fill many hours that children from economically advantaged families used to devote to spontaneous play.

Children of the Samburu people of Kenya join in a spontaneous game of soccer. In village societies in developing countries and in many low-SES communities in industrialized nations, children’s informal sports and games remain common.

In village societies in developing countries and in many low-SES communities in industrialized nations, children’s informal sports and games remain common. In an ethnographic study in two communities—a refugee camp in Angola, Africa, and a Chicago public housing complex—the overwhelming majority of 6- to 12-year-olds engaged in child-organized games at least once a week, and half or more did so nearly every day. Play in each context reflected distinct cultural values (Guest, 2013). In the Angolan community, games emphasized imitation of social roles—soccer moves of admired professional players, the intricate operation of a cooking spice shop. Games in Chicago, in contrast, were competitive and individualistic. In ballgames, for example, children often made sure peers noticed when they batted or fielded balls particularly well.

11.4.5 Adult-Organized Youth Sports

More than half of U.S. children—62 percent of boys and 52 percent of girls—participate in organized sports outside of school hours at some time between ages 6 and 12 (Aspen Institute, 2018). Children in low-SES communities, however, are profoundly underserved, with girls and ethnic minorities having especially limited opportunities. In a comparison of two neighborhoods in Oakland, California, 67 percent of teenage girls in a well-to-do area were members of athletic teams (Team Up for Youth, 2014). Just a few miles away, in a poverty-stricken, largely minority part of the city, a mere 11 percent were involved in organized sports. The high cost of equipment and uniforms (and, at times, travel) keeps many economically disadvantaged children from participating.

Joining community sports teams is associated with increased athletic and social skills, yielding benefits for participants’ self-esteem (Cronin, 2015; Wagnsson, Lindwall, & Gustafsson, 2014). Among shy children, sports participation seems to play a protective role, fostering self-confidence and a decline in social anxiety, perhaps because it provides a sense of group belonging and a basis for communicating with peers (Findlay & Coplan, 2008). And children who view themselves as good at sports are more likely to continue playing, which predicts greater participation in sports and other physical fitness activities in adolescence and early adulthood (Duncan, Strycker, & Chaumeton, 2015; Kjønniksen, Anderssen, & Wold, 2009; Marsh et al., 2007).

Look and Listen

Observe a youth athletic-league game, such as soccer, baseball, or hockey. Do coaches and parents encourage children’s effort and skill gains, or are they overly focused on winning? Cite examples of adult and child behaviors.

In some cases, though, the arguments of critics—that youth sports overemphasize competition and substitute adult control for children’s natural experimentation with rules and strategies—are valid. When coaches make winning paramount, weaker performers generally experience social ostracism. Children who experience poor-quality relationships with their coach and teammates enjoy sports participation less and soon drop out (Gardner, Magee, & Vella, 2017; Stryer, Tofler, & Lapchick, 1998). And those who join teams so early that the necessary skills are beyond their abilities also lose interest.

Parents, even more than coaches, influence children’s athletic attitudes and abilities. Positive parenting is consistently associated with children’s persistence and skill gains, whereas high parental pressure sets the stage for emotional difficulties and dislike of sports (Knight, Berrow, & Harwood, 2017). At the extreme are parents who value sports so highly that they punish their child for making mistakes, insist that the child keep playing after injury, hold the child back in school to ensure a physical advantage, or even seek medical interventions to improve the child’s performance.

A mother—who is also the coach of her daughter’s youth basketball team—runs a drill with the 10-year-old while her younger brother looks on. Positive parenting is consistently associated with children’s skill gains and persistence at sports.

In most organized youth sports, health and safety rules help ensure that injuries are infrequent and mild. An exception is football, which has a high incidence of serious injury. Eight- to 12-year-old boys in tackle football leagues experience rates of concussion—brain injuries resulting from a blow to the head or body—that equal those of high school and college players (Kontos et al., 2013). And in any sport, frequent, intense practice can lead to painful “overuse” injuries that, in extreme cases, cause stress-related fractures that impair physical growth (Brown, Patel, & Darmawan, 2017). On highly competitive teams with year-round training, overuse injuries are common.

Applying What We Know

Providing Developmentally Appropriate Organized Sports in Middle Childhood

Strategy

Description

Build on children’s interests.

Permit children to select from among appropriate activities the ones that suit them best. Do not push children into sports they do not enjoy.

Teach age-appropriate skills.

For children younger than age 9, emphasize basic skills, such as kicking, throwing, and batting, and simplified games that grant all participants adequate playing time.

Emphasize enjoyment.

Permit children to progress at their own pace and to play for the fun of it, whether or not they become expert athletes.

Limit the frequency and length of practices.

Adjust practice time to children’s attention spans and need for unstructured time with peers, with family, and for homework. Two practices a week, each no longer than 30 minutes for younger school-age children and 60 minutes for older school-age children, are sufficient.

Focus on personal and team improvement.

Emphasize effort, skill gains, and teamwork rather than winning. Avoid criticism for errors and defeat, which promotes anxiety and avoidance of athletics.

Discourage unhealthy competition.

Avoid all-star games and championship ceremonies that recognize individuals. Instead, acknowledge all participants.

Permit children to contribute to rules and strategies.

Involve children in decisions aimed at ensuring fair play and teamwork. To strengthen desirable responses, reinforce compliance rather than punishing noncompliance.

When parents and coaches emphasize effort, improvement, participation, and teamwork, young athletes enjoy sports more, exert greater effort to improve their skills, and perceive themselves as more competent at their chosen sport (Ross, Mallett, & Parkes, 2015). See Applying What We Know above for ways to ensure that athletic leagues provide children with positive learning experiences.

11.4.6 Shadows of Our Evolutionary Past

While watching children in your neighborhood park, notice how they occasionally wrestle, roll, hit, and run after one another, alternating roles while smiling and laughing. This friendly chasing and play-fighting is called rough-and-tumble play. It emerges in the preschool years and peaks in middle childhood, and children in many cultures engage in it with peers whom they like especially well (Pellegrini, 2004). After a rough-and-tumble episode, children continue interacting rather than separating, as they do after an aggressive encounter.

Children’s rough-and-tumble play resembles the social behavior of many other young mammals. It seems to originate in parents’ physical play with babies, especially fathers’ play with sons (see page 265 in Chapter 7). And it is more common among boys, probably because prenatal exposure to androgens predisposes boys toward active play (see page 378 in Chapter 10). Boys’ rough-and-tumble largely consists of playful wrestling and hitting, whereas girls tend to engage in running and chasing, with only brief physical contact. In middle childhood, rough-and-tumble accounts for as much as 10 percent of free-play behavior.

In our evolutionary past, rough-and-tumble play—which can be distinguished from aggression by its friendly quality—may have been important for developing fighting skill and establishing dominance hierarchies.

Nick Clements/Getty Images

In our evolutionary past, rough-and-tumble play may have been important for developing fighting skill. It also helps children form a dominance hierarchy—a stable ordering of group members that predicts who will win when conflict arises. Observations of arguments, threats, and physical attacks between children reveal a consistent lineup of winners and losers that becomes increasingly stable in middle childhood and adolescence, especially among boys. Once school-age children establish a dominance hierarchy, hostility is rare. Children seem to use play-fighting as a safe context to assess the strength of a peer before challenging that peer’s dominance (Fry, 2014; Roseth et al., 2007).

Rough-and-tumble play offers lessons in how to handle combative interactions with restraint. And as long as fathers’ physical play is warm, energetic, and appropriately challenging, it is associated with children’s favorable emotional and social adjustment and self-regulation (St George, Fletcher, & Palazzi, 2017; Fletcher, St George, & Freeman, 2013). High-quality rough-and-tumble seems to provide valuable opportunities for children to practice reading emotions, inhibiting impulses (such as hitting), and coping with frustration.

As children reach puberty, individual differences in strength become apparent, and rough-and-tumble play declines. When it does occur, its meaning changes: Adolescent boys’ rough-and-tumble is linked to aggression (Pellegrini, 2003). Unlike children, teenage rough-and-tumble players “cheat,” hurting their opponent. In explanation, boys often say that they are retaliating, apparently to reestablish dominance. Thus, a play behavior that limits aggression in childhood becomes a context for hostility in adolescence.

11.4.7 Physical Education

Physical activity supports many aspects of children’s development—their health, their sense of self-worth as physically active and capable beings, and the cognitive and social skills necessary for getting along with others. A large body of evidence links school-based physical activity to improved academic achievement (Centers for Disease Control and Prevention, 2017g; Donnelly et al., 2016). Yet to devote more time to academic instruction, U.S. elementary schools have cut back on recess (see the Social Issues: Education box on the following page).

Similarly, although most U.S. states require some physical education, only six require it in every grade, and only one mandates at least 30 minutes per school day in elementary school and 45 minutes in middle and high school. Nearly half of U.S. elementary and secondary school students do not attend any physical education classes during a typical school week. Not surprisingly, physical inactivity among children and adolescents is pervasive. Fewer than 30 percent of 6- to 17-year-olds engage in at least moderate-intensity activity for 60 minutes per day, including some vigorous activity (involving breathing hard and sweating) on three of those days—the U.S. government recommendations for good health (Centers for Disease Control and Prevention, 2014b; Society of Health and Physical Educators, 2016). With the transition to adolescence, physical activity declines, more for girls than for boys.

Many experts believe that schools should not only offer more frequent physical education classes but also change the content of these programs. Training in competitive sports, often a high priority, is unlikely to reach the least physically fit youngsters, who avoid activities demanding a high level of skill. Instead, programs should emphasize enjoyable, informal games and individual exercise (walking, running, jumping, tumbling, and climbing)—pursuits most likely to endure. Furthermore, children of varying skill levels are more likely to sustain physical activity when teachers focus on each child’s personal progress and contribution to team accomplishment (Society of Health and Physical Educators, 2009b). Then physical education fosters a healthy sense of self while satisfying school-age children’s need to participate with others.

In a lively game of barnyard tag, “animals” scatter to avoid being tagged by “farmers.” Many experts believe that physical education classes should emphasize informal games, as well as individual exercise and personal progress, rather than competitive sports.

Social Issues: EducationSchool Recess—A Time to Play, a Time to Learn

When 7-year-old Whitney’s family moved to a new city, she left a school with three daily recess periods for one with just a single 15-minute break per day, which her second-grade teacher canceled if any child misbehaved. Whitney, who had previously enjoyed school, complained daily of headaches and an upset stomach. Her mother, Jill, thought, “My child is stressing out because she can’t move all day!” After Jill and other parents successfully appealed to the school board to add a second recess period, Whitney’s symptoms vanished.

Over the past two decades, recess—along with its rich opportunities for child-organized play and peer interaction—has diminished or disappeared in many U.S. schools. Under the assumption that extra time for academics will translate into achievement gains, nearly one-third of school districts no longer require a daily recess for public school students (Centers for Disease Control and Prevention, 2017e).

Yet rather than subtracting from classroom learning, recess periods boost it! Research dating back more than 100 years confirms that extending cognitively demanding tasks over a longer time by introducing regular breaks, rather than consolidating intensive effort within one period, enhances attention and performance at all ages. Such breaks are particularly important for young children.

In a series of studies, school-age children were more attentive in the classroom after recess than before it—an effect that was greater for second than fourth graders (Pellegrini, Huberty, & Jones, 1995). And relative to nonparticipating agemates, second and third graders randomly assigned to a program of 10-minute periods of physical activity distributed across the school day scored substantially higher in academic achievement at a three-year follow-up (Donnelly et al., 2009). Teacher ratings of classroom disruptive behavior also decline for children who have more than 15 minutes of recess a day (Barros, Silver, & Stein, 2009).

In another investigation, kindergartners’ and first graders’ engagement in peer conversation and games during recess positively predicted later academic achievement, even after other factors that might explain the relationship (such as previous achievement) were controlled (Pellegrini et al., 2002). Consistent with these findings, industrialized nations offering more recess in elementary school tend to have students who attain higher achievement test scores when they reach high school (Yogman et al., 2018).

Recall from Chapter 10 that children’s social maturity contributes substantially to early academic competence. Recess is one of the few remaining contexts devoted to child-organized games that provide practice in vital social skills—cooperation, leadership, followership, and inhibition of aggression—under adult supervision rather than direction. As children transfer these skills to the classroom, they may join in discussions, collaborate, follow rules, and enjoy academic pursuits more—factors that enhance motivation and achievement.

Finally, school yards with spacious grassy play areas, a variety of playground equipment, and physically active adult models enhance children’s moderate-to-vigorous exercise during recess. Girls, who are less active than boys during recess, benefit especially from encouragement to engage in physically active games (Martin et al., 2012; Woods et al., 2015). In sum, regular, unstructured recess promotes children’s health and competence—physically, academically, and socially.

Fifth-graders play an energetic game of gaga ball (a variant of dodge ball) during recess. By providing regular opportunities for play and games, recess promotes physical, academic, and social competence.

Physically fit children take great pleasure in their rapidly developing motor skills. As a result, they develop rewarding interests in physical activity and sports and are more likely to become active adolescents and adults who reap many benefits (Kjønniksen, Torsheim, & Wold, 2008). These include greater physical strength, resistance to many illnesses (from colds and flu to cancer, diabetes, and heart disease), enhanced psychological well-being, and a longer life.

Ask Yourself

Connect ■ On Saturdays, 10-year-old Darnell gathers with friends on the driveway of his house to play basketball. Besides improved ball skills, what else is he learning?

Apply ■ Nine-year-old Jasmine thinks she isn’t good at sports, and she doesn’t like physical education class. Suggest strategies her teacher can use to improve her pleasure and involvement in physical activity.

Reflect ■ Did you participate in adult-organized sports as a child? If so, what kind of climate for learning did coaches and parents create? What impact do you think your experiences had on your development?

Summary

11.1 Body Growth (p. 405)

11.1a Describe changes in body size, proportions, and skeletal maturity during middle childhood.

School-age children’s growth extends the slow, regular pace of early childhood, although with substantial individual and geographic variation. By age 9, girls overtake boys in physical size.

In industrialized nations, final height has been increasing for the past 150 years, a secular trend in physical growth due mostly to improved nutrition and health.

Bones continue to lengthen and broaden, and permanent teeth replace primary teeth. Tooth decay affects more than half of U.S. school-age children, with especially high levels among low-SES children. One-third of school-age children suffer from malocclusion, requiring braces for some.

11.1b Describe brain development in middle childhood.

Brain weight increases by only 10 percent during middle childhood, but white matter rises steadily and gray matter peaks and then declines as a result of synaptic pruning. The resulting increase in interconnectivity among distant regions of the cerebral cortex and accompanying reorganization and selection of brain circuits leads to more effective information processing and, in particular, to gains in executive function.

11.2 Health Issues (p. 409)

11.2a Describe the causes and consequences of serious nutritional problems in middle childhood, giving special attention to obesity.

Poverty-stricken children in developing countries and in the United States suffer from serious and prolonged malnutrition, which can result in lasting physical, cognitive, and mental health problems.

Overweight and obesity have increased dramatically in both industrialized and developing nations. Although heredity contributes to obesity, environmental factors, including family stress, parental feeding practices, maladaptive eating habits, insufficient sleep, physical inactivity, excessive screen media use, and the broader food environment play substantial roles.

Obese children are at risk for lifelong health problems. Often socially rejected, they also display elevated rates of serious psychological disorders.

Family-based interventions aimed at changing parents’ and children’s eating patterns and lifestyles are the most effective approaches to treating childhood obesity. Schools can help by ensuring regular physical activity and serving healthier meals.

11.2b List factors that contribute to illness during the school years, and explain how these health challenges can be reduced.

The most common vision problem, myopia, is influenced by heredity, early biological trauma, and time spent reading, writing, and doing other close work. Although ear infections decline during the school years, repeated infections, particularly among low-SES children, result in some hearing loss.

Heredity is a major contributor to nocturnal enuresis, though early difficult temperament elevates risk for the problem. The most effective treatment is a urine alarm that works according to conditioning principles.

The prevalence of asthma, the most frequent cause of school absence and hospitalization in U.S. children, has been steadily increasing. Urban pollution, stressful home lives, childhood obesity, and lack of access to good health care contribute to the illness. Its rate and severity are greatest among boys and children who live in poverty.

Children with severe chronic illnesses are at risk for academic, emotional, and social difficulties, but positive family relationships improve adjustment.

11.2c Describe changes in the occurrence of unintentional injuries during middle childhood, and cite effective interventions.

Unintentional injuries increase over middle childhood and adolescence, especially for boys, with motor vehicle and bicycle accidents accounting for most of the rise. Children are unrealistically optimistic about their likelihood of injury, making parental supervision key to injury prevention.

Effective school- and community-based safety education programs use modeling and rehearsal of safety practices and reward children for good performance. Insisting that children wear protective bicycle helmets dramatically reduces the risk of serious head injury.

11.3 Health Education (p. 418)

11.3 Identify steps that parents and teachers can take to encourage good health practices in school-age children.

Besides providing health-related information, adults must reduce health hazards in children’s environments, coach children in good health practices, and model and reinforce these behaviors.

11.4 Motor Development and Play (p. 420)

11.4a Cite major changes in gross- and fine-motor development during middle childhood.

Gains in flexibility, balance, agility, and force contribute to improved athletic performance during middle childhood.

More efficient information processing plays a vital role in children’s improved gross-motor performance. Physical exercise, in turn, enhances brain and cognitive functioning.

Fine-motor development also improves. Handwriting becomes more legible, and children’s drawings show dramatic increases in organization, detail, and representation of depth.

11.4b Describe individual differences in motor performance during middle childhood.

Wide individual differences in children’s motor capacities reflect the influence of both heredity and environment, including such factors as body build, parental encouragement, and access to lessons and athletic equipment.

Gender stereotypes, which affect parental expectations for children’s athletic performance, largely account for school-age boys’ superiority on a wide range of gross-motor skills. Greater emphasis on skill training for girls and attention to their athletic achievements can help increase their involvement and performance.

11.4c Describe qualities of children’s play that are evident in middle childhood.

Games with rules become common during the school years, contributing to emotional and social development. Participation in adult-organized youth sports programs is associated with increased self-esteem and social competence in most players, but low-SES children have limited access to such programs. Adult pressure to perform and overemphasis on competition promote undue anxiety and avoidance of sports in children.

Some features of children’s physical activity reflect our evolutionary past. Rough-and-tumble play may once have been important for developing fighting skill and helps children establish a dominance hierarchy. In middle childhood, dominance hierarchies become increasingly stable, especially among boys, and serve the adaptive function of limiting aggression among group members. Warm, energetic rough-and-tumble play with fathers is associated with children’s favorable adjustment and self-regulation.

11.4d Identify steps that schools can take to promote physical fitness in middle childhood.

In addition to providing an opportunity for physical activity, school recess is a rich context for child-organized games and social interaction.

U.S. elementary schools have cut back on recess and physical education classes, despite the benefits that exercise and play offer for physical health, academic achievement, social skills, and psychological well-being.

IMPORTANT TERMS AND CONCEPTS

dominance hierarchy (p. 426)

malocclusion (p. 407)

nocturnal enuresis (p. 415)

obesity (p. 410)

rough-and-tumble play (p. 425)

secular trends in physical growth (p. 407)