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1The Science of Psychology

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Focus Questions

By the end of the chapter, you should be able to answer the following questions:

ሁ How is psychology defined? ሁ What are the principal responsibilities of members of the main divisions in psychology? ሁ What were the key contributions of psychology’s early pioneers? ሁ What are some of the main sources of psychological information? ሁ What are the identifying characteristics of the scientific method? ሁ What are some key types of descriptive research? ሁ How does descriptive research differ from experiments and ex post facto studies? ሁ What is the correlation fallacy? ሁ What are some of the main sources of error in interpreting the results of psychological

investigations?

Section 1.1What Is Psychology?

Chapter Outline

1.1 What Is Psychology? 1.2 Early Origins of Psychology

Structuralism Functionalism

1.3 Current Approaches to Psychology Behaviorism Psychodynamic Theory Cognitivism Humanism Sociocultural Perspective Biological/Physiological/Psychological

Approaches 1.4 Psychology as a Science 1.5 Sources of Psychological

Information

Descriptive Research Correlational Research Experiments Ex Post Facto Studies

1.6 Interpreting Psychological Research Experimenter Bias Subject Bias Sampling Bias The Correlation Fallacy Other Problems of Psychological

Research 1.7 Philosophical Issues and

Psychological Controversy 1.8 The Relevance of Psychology 1.9 This Book

The purpose of psychology is to give us a completely different idea of the things we know best.

—Paul Valéry, Tel Quel, 1943

My grandmother was convinced she knew best. “Not true,” she would declare when I tried to tell her what I was learning as a novice psychology student. And then, her needles clacking, she would go on to inform me that boys who mature early are always messed up later. She also believed that people use only 10 percent of their brain because that is what she had read some- where. And she knew that those suffering from mental disorders are like night and day from her and other sane people. Nor did she trust psychologists: “They have sneaky ways of looking into people’s minds,” she informed me. “Except they have no power over people who have ESP.”

“And mark my word,” she said one time, “most geniuses are crazy.” “But you don’t have to worry,” she added.

1.1 What Is Psychology? These and a wide range of similar beliefs make up what is sometimes called bubba psychol- ogy (bubba or bubbe—or sometimes bubbie—means grandmother in some Eastern European languages). Bubba psychology is also labeled naïve psychology or folk psychology. It is made up of our unexamined, intuitive beliefs about people and human behavior, and should not be confused with pop psychology. Pop—or popular—psychology is made up of concepts and theories about human behavior that are purported to be founded on academic psychology but that are instead based on simplistic and superficial interpretations that are popularized in magazine articles and by radio and television personalities. Pop psychology has prolifer- ated in online self-help sites, talk shows, advice columns, and television and movie dramas.

Section 1.1What Is Psychology?

Unlike bubba (or folk) psychology, pop psychology pretends to be the real thing, although from a scien- tific point of view, it is generally considered to be a form of pseudopsychology.

Psychological research has not been kind to many of my grandmother’s beliefs—which is not to say all our folk wisdom is untrue or that psychology’s beliefs are always correct. In fact, much of our folk wisdom is correct; and psychology, like most sci- ences, does occasionally change its mind.

My grandmother’s belief that psychologists have devious ways of peering into one’s mind is one rea- son why it is important to have a clear understand- ing of what psychology is and is not. While it is true that the goal of psychology is to solve the puzzles of human thought and behavior, it is a science and not a collection of special powers.

In its simplest sense, psychology is the science that studies human behavior and mental processes. Unfortunately, this definition does little justice to the tremendous variety of activities and interests that make up the field. In fact, the nearly 90,000 members of the American Psychological Associa- tion (APA) divide themselves into 54 different divi- sions (APA, 2014a). These divisions reflect different interests and specializations such as the study of aging or the application of psychological knowledge and principles in clinical settings. Almost 58 per- cent of APA members are women.

What different psychologists do varies a great deal. As Figure 1.1 shows, the vast majority of psychologists are involved in the practical application of psychological knowledge. Nearly 40 percent of all psy- chologists are clinical psychologists. These are typically psychologists working in a hospital or clinical setting. They specialize in helping people with psychological prob- lems such as anxiety, depression, addiction, or relationship problems.

Although clinical psychologists and psychi- atrists often treat similar sorts of problems, the training and expertise of each is quite different. Psychiatrists are medical doctors with specialized training in identifying and

Photos.com/Thinkstock ሁ Psychology, like most sciences,

occasionally changes its mind. We no longer believe that the bumps and lumps on our skulls are roadmaps to our personalities, although early in the 19th century, we were pretty certain that was the case.

Pamela Moore/Getty Images ሁ Nearly half of all psychologists are clinical

psychologists specializing in helping people with psychological problems. Unlike psychiatrists, they are not usually medical doctors and cannot typically prescribe medication.

Section 1.1What Is Psychology?

treating mental and emotional disorders (discussed in Chapter 10). In addition to the various other interventions they might use, they can prescribe drugs, which are now commonly used to treat many disorders ranging from mild anxiety to severe deviations from normality. In most jurisdictions, clinical psychologists cannot write prescriptions.

Figure 1.1: Main specialties in psychology ሁ There are 54 recognized specialties in psychology. The interests and activities of many

psychologists place them in more than a single category.

Counseling 5.8%

School 2.5%

Educational 1.3%

Industrial/Organizational 3%

Health 1.3%

Developmental 1.8%

Experimental 0.8%

Social 1.5%

Other 42.9%

Clinical 39.1%

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Source: Based on a survey of the American Psychological Association’s 80,067 members in 2014. Data from APA Member Profiles, 2014, Table 3. Retrieved March 10, 2015, from http://www.apa.org/workforce/publications/14-member/index.aspx?tab=2. Published by American Psychologizl Association. Reprinted with permission.

A significant number of psychologists are counseling psychologists who sometimes treat problems related to emotional and mental disorders or who specialize in issues such as those having to do with vocational choices, learning problems, relationships, and related concerns.

Industrial/organizational psychologists are concerned mainly with work-related issues such as determining how to hire the right person for a job, improving job satisfaction, increas- ing motivation in the workplace, reducing stress, and managing goals.

School psychologists deal with behavioral and learning problems that affect school children and are often called upon to administer tests, to diagnose learning and behavioral problems, and to suggest treatment for these problems.

Psychologists concerned specifically with improving teaching and learning are educational psychologists. Unlike school psychologists, they are less concerned with individual behav- ioral and learning problems than with broader questions relating to how people learn in edu- cational settings. Educational psychology applies psychological principles to classroom man- agement, special needs education, instructional design, and lesson planning.

Developmental psychologists study systematic changes that occur between conception and death. Some specialize in the study of child development; others are more concerned with adolescent or adult development, or with aging and dying.

Section 1.1What Is Psychology?

Much of the content of psychology—and therefore of this text—is based on the work of experimental psychologists. They specialize in the use of experimental methods to inves- tigate the puzzles of psychology. Most of the psychological information that is the basis for other specializations (such as clinical, social, or cognitive psychology) is based on the findings of experimental psychologists.

Psychology also has a large number of other specializations: Sports psychologists use psycho- logical research to improve athletic performance; forensic psychologists are usually experts in criminal law as well as in psychology and might be called upon to assist in jury selection or as expert witnesses for assessing the state of mind of the accused at the time of the offense or the defendant’s competency to stand trial; personality psychologists specialize in studying the characteristics that distinguish one person from another; social psychologists are concerned with the importance of membership in groups; cognitive psychologists study mental processes such as thinking, imagining, and problem solving; and environmental psychologists look at the relationship between humans and their surroundings, and specifically at the effects of the environment on our well-being (Table 1.1).

Table 1.1: What psychologists do

Some major divisions Primary focus Example of possible activities

Clinical Diagnosing and treating emotional illnesses and disorders

Conducting patient evaluations, frequently in a hospital or clinical setting

Counseling Evaluating and assisting with behavioral, emotional, and other problems not serious enough to require hospital, clinical, or psychiatric treatment

Assisting with important decisions such as those having to do with careers, relationships, adjustment, and stress

Industrial/organizational Applying psychology in business and industry

Developing and administering tests to evaluate aptitudes; dealing with motivational, management, and interpersonal issues in the workplace

School Identifying individual aptitudes and skills among learners in a school setting

Developing and administering tests pertinent to school-related abilities; diagnosing and remediating behavioral and learning problems

Educational Researching the application of psychological principles for improving teaching and learning

Carrying out an investigation of two specific approaches to teaching

Developmental Studying changes that define growth, learning, and maturation from birth to death

Applying findings in educational programs and in child guidance and counseling

Experimental Carrying out experimental investigations in a variety of different areas to provide useful information for more applied or more theoretical psychologists

Studying the effects of psychoactive drugs on memory

Section 1.2Early Origins of Psychology

Enormous overlap exists among the interests and activities of psychologists who belong to the APA’s 54 different divisions. Regardless of their specialization, many psychologists write books, teach, do research, conduct private practices, work in business and industry, or are employed in a variety of different professions where knowledge of psychology is useful and sometimes even essential. Most are engaged in a combination of activities.

1.2 Early Origins of Psychology The history of psychology goes back at least as far as ancient Greece, when the discipline of philosophy embraced almost all other disciplines including what is now known as psychol- ogy. In fact, the term psychology derives from the Greek words psyche, which means “soul,” and logos, which means “the study or discussion of.” Philosophy is now concerned mainly with the nature of reality, knowledge, and values, and with systems of logical reasoning. Psy- chology, as we saw, studies human behavior and mental processes.

More recently in the history of psychology, discoveries in medicine have had a dramatic influ- ence on our conception of the human being. When William Harvey discovered that the heart pumps blood into tubes throughout the body, many thinkers became convinced that people were nothing more than elaborate pumping machines. Some very wise people suspected that the ability to think originates in the blood. Aristotle did not merely suspect this—he was convinced of it. If a person’s blood were entirely removed, he argued, no evidence of thinking would remain!

Early physics, too, contributed to the development of psychology. The psychological impor- tance of Sir Isaac Newton’s observation that apples invariably fall earthward lies in the fact that it illustrates a different way of looking at natural phenomena. The ancient Greek phi- losophers undoubtedly knew that apples fall earthward. And had they wanted to know why apples fall, they might have thought long and hard about the problem and held learned dis- courses with colleagues. But their approach would have made little use of the methods of science as we now know them—methods whose hallmark is objectivity and replicability. Unlike the early Greeks, Newton felt compelled to demonstrate and verify the phenomena he observed and to investigate them by means of controlled experimentation. We are products of Newton’s generation: Psychology, anthropology, sociology, and other related fields are sel- dom referred to as the social studies; they are the social sciences.

Scientific psychology is not quite a century and a half old. Its founder is generally consid- ered to be Wilhelm Wundt, who set up the first psychological laboratory in Leipzig, Germany, in 1879. Many of Wundt’s students later established laboratories of their own throughout Europe and North America. Soon after that, psychology departments opened at all major uni- versities. Typically these began as branches of departments of philosophy, but in time the discipline became totally separate. Departments of psychology now claim far more students than do departments of philosophy.

Structuralism The early history of psychology is marked by the rise—and fall—of a number of different “schools” of thought. The first dates back to Wilhelm Wundt and his followers, whose search for pieces of the human puzzle relied on introspection. Introspection involves looking inside oneself, examining one’s own thoughts, feelings, and motives and generalizing the resulting

Section 1.3Current Approaches to Psychology

insights to understand the thoughts and feelings of others. Stop, for a moment, and think about the words you are now reading. How does a physical stimulus such as a word on a page affect you? As you carefully analyze your current thoughts and feelings, you are introspecting.

The goal of introspection as practiced by Wundt and his followers was to understand the structure of thoughts, emotions, and motives. For example, participants would be exposed to a stimulus such as a sound or a light and would be asked to report their thoughts and sensa- tions. Wundt’s goal was to analyze and measure reactions and reaction times. He reasoned that the conscious mind, like any other natural object, must comprise identifiable, measur- able elements. In the same way that water is made up of two atoms of hydrogen and one of oxygen, so too must sensations and feelings be made up (structured) of basic mental ele- ments. One of Wundt’s students, Edward B. Titchener, named this approach structuralism.

Functionalism William James, widely credited with being the founder of American psychology, thought it a waste of time to try to explain the mind by looking at its structure. Heavily influenced by Charles Darwin’s new theories, James argued that it would be far better to try to determine the purposes that drive behavior—that is, its functions: hence, the label functionalism.

James’s 1,000-page book, The Principles of Psychology (1890), did a great deal to establish what psychology would become. It is James, for example, who first wrote of the “stream of consciousness” and of the baby’s world as “one great blooming, buzzing confusion.” Among the topics in his book are will, interest, emotions, sensation, the brain, and, of course, the stream of consciousness. He asked questions such as “How can people strengthen habits?” “How does intention motivate action?” and “What is memory and how does it work?”

1.3 Current Approaches to Psychology More recent approaches to psychology take a variety of forms, most of which have their roots in earlier movements and emphases—but with a number of important differences. For exam- ple, although James’s functionalism profoundly influenced the subsequent development of psychology, by the early 1900s, many psychologists, especially in the United States, had begun to reject difficult and subjective topics such as mind and thinking.

Behaviorism Led by John Broadus Watson, a group of psychologists moved away from trying to answer difficult questions relating to mental processes, choosing instead to concentrate on the objec- tive, observable aspects of behavior: hence, the label behaviorism. Behaviorism, explains Moore, “emphasized publicly observable stimuli (s) and responses (r) and spurned suppos- edly unobservable, centrally initiated processes like consciousness” (2010, p. 143).

Among the most important behaviorists are Watson and Skinner. Behaviorists tend to study reflexive behavior and the effects of the consequences of behavior. As we see in Chapter 5, many scientific experiments can be carried out to investigate these matters. As a result, with the advent of behaviorism, psychology became progressively more scientific. But because of its emphasis on discovering how behavior is controlled by stimuli and by its consequences, behaviorism is sometimes interpreted as denying the existence of free will.

Section 1.3Current Approaches to Psychology

Psychodynamic Theory At about the same time that the behaviorists were first popular in American psychology, the Austrian neurologist Sigmund Freud was developing startling new ideas about the mind. As explained in Chapter 9, Freud believed that the mind is a little like an iceberg: We see only the very tip, which represents the conscious mind; the bulk of it is hidden, unconscious. Much of our behavior is driven by unconscious forces: They lie beneath the visible iceberg, beyond our conscious awareness. Freud believed that many of our emotional disorders stem from these

unconscious psychodynamic forces. There are methods of analysis, of psychoanalysis, explained Freud, that can uncover these hidden motives and forces. As we see in Chapter 10, Freudian therapy is based squarely on the notion that consciously rec- ognizing and talking about hidden motives and deep-seated conflicts can lead to the alleviation of mental disorders.

Cognitivism Other psychologists rejected the narrow emphases of a behaviorism that limited itself to observable events, but relatively few embraced Freud’s psycho- analysis. Many can be described as belonging to the school labeled cognitivism. These are psycholo- gists whose main concerns are with intellectual (cognitive) events such as problem solving, think- ing, information processing, and imagining. Cog- nitivism provides explanations for behavior based on our ability to symbolize, to uncover cause-and- effect relationships, to determine what goes with what, and to anticipate the consequences of our actions.

Humanism Some psychologists object to what they see as the overly limited, mechanistic, and dehu- manizing emphases of behavioristic approaches to psychology. Too, they reject the Freudian notion that we are driven by dark, unconscious forces over which we have little control. These approaches, they argue, pay too little attention to the positive and healthy aspects of human nature. Humanistic psychology, as we see in Chapter 9, is concerned with the uniqueness and self-determination of each person. It emphasizes the development of the “self,” and is represented by psychologists such as Abraham Maslow and Carl Rogers.

Stockbyte/Thinkstock ሁ Psychoanalysts are psychiatrists who,

like Freud, believe that mental disorders result from deep-seated psychodynamic conflicts. The purpose of the couch is to allow the patient to relax so as to facilitate uncovering these conflicts—often through free association or dream analysis.

Section 1.3Current Approaches to Psychology

Humanism arose primarily as a reaction against behavioristic and psychodynamic theo- ries, which Maslow (1987) described as the two great forces in psychology, so he labeled the humanistic movement third force psychology. His hope was that this third force would become as powerful as the first two, and that it might counter the dehumanizing influence of a rigorous scientific approach to the study of psychology.

Sociocultural Perspective Human behavior is highly influenced by membership in cultural and social groups. For exam- ple, as we see in Chapter 4, your gender is very closely related to your beliefs, values, and behaviors. Similarly, your ethnicity, religion, social class, and peer groups exercise profound influences on who you are and how you act. Chapter 8, which deals with social psychology, explores the power of social groups and influences and looks at how these can affect your attitudes, opinions, and behaviors. Concern with the influences of cultural and social groups and subgroups defines the sociocultural perspective in psychology.

Biological/Physiological/Psychological Approaches There are a number of other important orientations in the study of psychology. Evolution- ary psychology is marked by an emphasis on biology and genetics as a source of explana- tions for human learning and behavior. Evolutionary psychologists look at the evolution of human behavior and try to explain human characteristics in terms of historical pressures of adaptation.

Neuroscience is another important and highly current, biologically based orientation. Using powerful new brain-imaging techniques, neuroscientists look to the nervous system, espe- cially the brain, for explanations of consciousness and of mental processes like thinking, imagining, problem solving, and remembering. Both evolutionary psychologists and neuro- scientists make extensive use of genomics, the study of genes and how they relate to human behaviors and characteristics.

Other models, like the biopsychosocial model, are general approaches that attempt to take into account all the forces that are involved in human thought and behavior. Biopsychosocial approaches, which are often found in areas of psychology that deal with human health, view behavior as a combined function of three classes of influences: biological (genetics, hormones, and other physical characteristics), psychological (thoughts and emotions), and sociocultural (ethnicity, culture, social group membership). (See Figure 1.2.)

Section 1.4Psychology as a Science

Figure 1.2: Historical and current approaches in psychology ሁ Orientations in the study of human behavior and mental processes.

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Structuralism Used introspection to try to discover the basic elements (the structure) of the mind (Wilhelm Wundt)

Functionalism Emphasized an exploration of the purposes (functions) of behavior (William James)

Behaviorism Concentrates on observable behavior (responses), its causes (stimuli), and the forces that shape it (such as its consequences) (John Watson; Fred Skinner)

Psychodynamic theory

Looks at the interplay of unconscious, instinct-based forces, especially as they relate to mental disorders (Sigmund Freud)

Cognitivism Focuses on intellectual (cognitive) events, such as thinking, problem solving, imagining, symbolizing, and anticipating (Jean Piaget; Albert Bandura)

Humanism Rejects the dehumanizing emphases of more “scienti�c” approaches; stresses the uniqueness and the positive characteristics of the individual (Abraham Maslow; Carl Rogers)

Sociocultural perspective

Tries to understand human behavior by looking at the in�uence of the social and cultural groups to which the individual belongs

Biological/ physiological/ psychological orientations

Looks at genetic contributions to human characteristics and behaviors; explores the relationship between human physiology—especially the brain and nervous system—and human psychology; one orientation, the biopsychosocial approach, looks at a combination of biological, psychological, and social in�uences

1.4 Psychology as a Science Psychology is a science, but what does that mean?

In one sense, science can mean a collection of information in a field of study. For example, the science of physics is a collection of information about the nature of matter and energy and how they interact. And the science of psychology is a collection of information about human thought and behavior and how they interact.

Section 1.4Psychology as a Science

In another very important sense, science is a way of dealing with information. As such, it is both an attitude and a set of guidelines that insist on objectivity, precision, and consistency. As a result, science stands in sharp contrast to ways of knowing that are based principally on subjective analysis or introspection.

Attempts to explain and organize the observations of science take the form of theories. Theo- ries are collections of related statements that clarify observations and permit predictions (hypotheses). Put another way, hypotheses are preliminary attempts to answer questions; they are tentative predictions that are made before extensive and thorough investigation. Theories, by contrast, are the result of careful research; they summarize and organize the findings of science.

In spite of science’s preoccupation with matters that are objective, many topics of interest to psychology cannot be observed and measured directly, but can only be inferred from behav- ior or from highly subjective self-reports. Emotions and thoughts, for example, are subjective rather than objective. And even though these might lead to behavior from which an observer might guess the underlying emotion or thought, this is not always so. For example, I might be very angry or very sad because I now know for sure that my dog does not much like me; but you would not necessarily know my emotion from my behavior because I can easily pretend I do not care.

One of the tasks of psychology is to devise ways of examining nonobjective events and states, and of studying them as objectively and scientifically as possible.

Studying phenomena objectively and scientifically means using what is often labeled the sci- entific method—an approach designed to ensure that observations are as accurate and valid as possible and that they can be replicated by other investigators. The sciences have now been using the scientific method for more than a hundred years to find and assemble pieces of the human puzzle. It can be described in terms of five systematic steps (Figure 1.3):

1. Ask a question. (For example: Would after-school detention be effective in stopping a group of boys from stealing iPods and smartphones?)

2. Develop a hypothesis. On the basis of observation and a careful examination of relevant investigations and theory, make a prediction—a hypothesis. By definition, a scientific hypothesis is unproven and can be falsified (proven incorrect). Hence, the outcome of a scientific investigation can lead to the rejection of the hypothesis. (Hypothesis: After-school detention will be effective in curtailing thefts of electronic devices.)

3. Collect relevant observations. As we see in the next section, science suggests many different ways to collect observations. The nature of the question being asked, as well as constraints related to money, time, instrumentation, and the availability of suitable participants, usually determine which method is best. (Method: Detain the group of thieves after school; monitor subsequent thefts.)

4. Analyze observations to test the hypothesis. Do your observations indicate that the hypothesis should be rejected? Even if they do not, might these observations be due to chance? Science is very concerned that outcomes might be just chance happen- ings, in which case, they do not mean very much at all. For this reason, investigators often use special statistical procedures to determine whether observations are sta- tistically significant. These are mathematical procedures that allow investigators to determine the likelihood that the outcomes of experiments are due to factors other

Section 1.4Psychology as a Science

than chance. (For example: How many devices disappeared before the detention? How many disappeared after?)

5. Reach and share conclusions. If science is to progress, the hypothesis has to be rejected or not rejected. If it is not rejected, it may be accepted as tentatively valid (we can seldom be absolutely certain). (For example: As many electronic devices disap- peared after as before detention. Tentative conclusion: Detention is not an effective deterrent in this case.) Following this, the conclusions of the research need to be shared. This means communicating the findings to others so they can apply them, and so they can continue the research and learning process.

Figure 1.3: Five common steps of the scientific method ሁ Science insists on precision, objectivity, and replicability. These five steps increase the likelihood

of meeting these conditions.

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Ask a question.

Develop a hypothesis.

Collect relevant observations.

Analyze observations to test the hypothesis.

Reach and share conclusions.

Is after-school detention effective in stopping a group

of boys from stealing electronics?

After-school detention will curtail thefts of electronic devices.

Detain the group of boys after school; monitor subsequent thefts.

Note and compare the number of electronic devices that disappeared

after and before detention.

Detention is not an effective deterrent in this case.

Section 1.5Sources of Psychological Information

1.5 Sources of Psychological Information The ways psychologists gather observations vary greatly depending on the topic being researched and sometimes on the psychologist’s preferences. What is invariably true, how- ever, is that observation is the source of all psychological knowledge, just as it is the source of knowledge in other sciences. Psychological studies and experiments vary according to who is being observed, when, how, and under what conditions. Thus, there is research designed simply to describe (descriptive research); other research might be meant to discover relation- ships (correlational research); and some might be aimed at identifying causes (experimental research).

Descriptive Research Descriptive research is used to describe the characteristics of an individual or of a group. It answers the questions who, what, where, when, and how. What is the average age of a group? How common is bipolar disorder? What is the current life expectancy in North America?

Descriptive research is often based on the results of archival research—research that depends on secondary sources such as census data, birth certificates, or other forms of past records. It may also be based on the results of naturalistic observation, case studies, or surveys.

Naturalistic Observation Naturalistic observation is observation that occurs in common, real-life settings rather than in settings such as clinics, laboratories, or hospitals. Naturalistic observation is well illustrated by the research of Dame Jane Morris Goodall who, beginning in 1960, lived among chimpan- zees in the Gombe Stream Research Centre in Tanzania for some 45 years, simply observing chimpanzees without disturbing them. The assumption of naturalistic observation is that if the investigator does interfere, the behavior under examination may be affected. (In sci- ence, an assumption is a belief that often guides thinking and research, and that is accepted as fact although it is often unproven and sometimes unprovable.) For example, chimpanzees that would be playful and bold in their natural state might become anxious and furtive when observed too closely.

Naturalistic observation takes place in surroundings that are not altered by the observer or by the requirements of the observation; nonnaturalistic observation occurs in more con- trived surroundings such as laboratories. Both are important in psychological investigation.

Naturalistic and nonnaturalistic approaches to gathering psychological information can be classified in terms of who is observed and how and when the observations are made. Thus, there are case studies, where single individuals (or single units such as a family) are observed and perhaps interviewed; and surveys, where large groups of individuals (or larger groups of units such as a number of families) are studied.

Studies can also be differentiated in terms of when observations are made. When the goal of psychological investigation is to identify changes that occur within individuals over time, longitudinal studies may be used. A longitudinal study examines the same individual(s) at different times and makes direct comparisons between the individual(s) at this point in time and the same individual(s) at an earlier time. As Figure 1.4 illustrates, longitudinal studies sometimes span many years and are therefore very time consuming and expensive.

Section 1.5Sources of Psychological Information

Figure 1.4: Longitudinal studies ሁ Studies that follow the same individuals over a period of time are longitudinal. They are useful for

identifying changes that occur over time, such as changes in Adam’s measured IQ with increasing age.

Longitudinal studies provide information about one or more individuals over a period of time. But they are expensive and time consuming. Many cannot be completed in the lifetime of a single investigator.

How stable is an individual’s IQ?

A d

a m

’s I Q

Adam’s age (years)

140

120

100

0 5 10 15 20 80...

f01.04Whereas longitudinal studies examine the same individuals over a span of years, cross- sectional studies examine two or more groups of participants at the same time. For example, psychologists who want to study age differences in the problem-solving strategies of children often use a cross-sectional approach. Thus, a typical study might compare strategy use among groups of 4-, 6-, and 8-year-old children. This approach might make age-related changes in strategy readily apparent. A longitudinal approach to the same question would require that investigators study the same group of children from ages 4 to 8. As a result, the research would require at least 4 years to complete. Hence, cross-sectional studies are much less time consuming and consequently much less expensive than longitudinal studies; but they are not always appropriate for answering questions about changes that occur within individuals over time. As Figure 1.5 shows, cross-sectional studies are often used for comparing groups at one point in time but are less useful for investigating the effects of time-related factors.

Figure 1.5: Cross-sectional studies ሁ Studies that look at different individuals at a given point in time are cross-sectional. They are

useful for comparing different groups. The study illustrated here looks at how average intelligence test scores might peak at different levels for different age groups.

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Cross-sectional studies can provide information about different groups at the same time. But, like surveys, they provide statistical averages and may not take all variables into account. For instance, did the 70-year-olds grow up with the same develop- mental stimulation as 35-year-olds, or 5-year-olds?

Does IQ peak at different ages?

60 80 100 120 ... IQ

N u

m b

e r

o f

in d

iv id

u a ls

35-year-olds

70-year-olds

5-year-olds

Torrance’s study of creativity, in which subjects were followed from childhood beginning in 1958 through a period of 50 years, provides one of the better known examples of longitudinal research in psychology (Millar, 2001, 2010). Investigators kept track of all creative

Section 1.5Sources of Psychological Information

accomplishments of each individual in the group: books written, art exhibitions, soft- ware programs, inventions, invited lectures, leadership positions, and so on. This inves- tigation found that highly creative children tend to become highly creative adults. The most highly gifted grew up to be college presidents, inventors, doctors, diplomats, and lawyers. Strikingly, their scores on mea- sures of creativity were far more predictive of their eventual accomplishments than were their scores on intelligence tests (Plucker, 1999).

Case Studies Descriptive research, as noted, can be based on case studies. A classic example of a case study is that of a young Russian, known to us only as S, who presented himself to a psycholo- gist one day. S was confused and poorly adjusted. He hoped that the psychologist, the very well-known and highly respected Alexandr Romanovich Luria, would help him (Luria, 1968). His problem was that he had difficulty following ordinary conversations, that his mind was such a jumble of sights and sounds that he was often absolutely overwhelmed and bewildered. From this initial meeting there developed a long relationship between the two, during which Luria conducted intensive and detailed investigations of S’s memory. Luria soon discovered that S could remember with incredible and uncanny accuracy. Nor did he remember as you or I might, painfully retrieving some isolated bit of information that we have succeeded in stor- ing and protecting from the ravages of time. He could remember in infinite detail, retrieving from his memory not only the item requested of him, but a host of other associations that most people would not even have noticed initially, let alone remembered.

As an example, one day Luria presented S with a table of 50 single-digit numbers. S spent three minutes examining the array. He then reproduced the entire table in 40 seconds, and could read off any number it contained in horizontal, vertical, or diagonal arrangements. Per- haps even more amazing, when S was asked to reproduce the same table several months later (the table had not once been presented in the interim), he could do so unerringly and just as rapidly.

As a result of this intensive and prolonged case study, Luria discovered that S did not simply hear sounds but sensed them as vivid and colorful images; that he could remember the cloth- ing he and Luria had been wearing on a given day years before; that he frequently remem- bered by “seeing” objects, events, or numbers in mental images of places where he had stored them. Sometimes he would imagine he was walking along a very familiar street in his home- town, and he would mentally place different numbers on various fences, trees, and houses along this street. Later, when called upon to remember these numbers, he would simply imag- ine the street and read off the numbers as he saw them. On one occasion when he could not recall a number he had memorized in this fashion, it eventually occurred to him that he had “placed” the number in question on a dark, heavily shaded piece of broken board and that he simply could not “see” it!

Photodisc/Thinkstock ሁ Naturalistic observation involves as little

interference with ongoing activities as possible and occurs in “natural” environments such as schools or, as shown here, playgrounds.

Section 1.5Sources of Psychological Information

S presents a classic case of what is termed synesthesia, a condition in which one sensation evokes another related to a different sense. For example, a person with synesthesia might hear a color or see a taste or an odor. It seems that S’s synesthesia provided him with an extraordi- narily vivid assortment of visual images that later became keys to his memory.

Luria’s investigation of S’s memory and his subsequent reports of the results of this investi- gation provide us with a striking example of a case study. Numerous other examples can be found in psychological literature, especially in studies of abnormal behavior. Whenever a psy- chologist requires extensive and in-depth information about a single individual, a case-study approach is likely to be used.

Surveys Descriptive studies are often based on surveys. Whereas a case study involves a single indi- vidual (or a single unit) studied in depth and often over a long period of time, surveys involve groups of individuals or groups of units who are typically not studied in as much detail or for as long a period. Case studies are often inappropriate when the intent is to describe a group of people. A psychologist who wants to know what the average person in the street thinks of a political event cannot easily accomplish this by walking up to and questioning an “average” person. In the first place, there is no average individual: He or she is an invention, a mathematical distillation. The researcher’s average person is never a single person but is, instead, the nonexistent, idealized “averaged” result of investigating many individuals. Figure 1.6 illustrates how surveys are often used to provide general information about a group.

Figure 1.6: Surveys ሁ Surveys are studies that look at characteristics among large groups. They are useful for providing

a quick summary of major group characteristics—such as, in this case, the average IQ of an identifiable group.

Surveys reveal information about groups of individuals at a speci�c time. But a single survey provides no information about change over time and it gives only a composite picture of an idealized “average” individual.

What is the average American IQ?

60 80 100 120 140 ...N u

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f01.06 A survey is a research technique that attempts to discover the qualities of the average person by examining the characteristics of a number of real individuals. What is especially impor- tant in doing a survey is that those being surveyed be representative of the entire group to which investigators want to generalize their findings. Generalization is the process of apply- ing findings or conclusions based on one or more cases to a larger number of cases. It is the objective of most scientific investigations. When researchers wanted to discover the sexual beliefs and behaviors of the average British 16- to 44-year-old, they interviewed and gave

Section 1.5Sources of Psychological Information

computer-based questionnaires to 11,161 individuals (Gerressu, Mercer, Graham, Wellings, & Johnson, 2008). They were then able to state that 73 percent of men and 37 percent of women had masturbated at least once in the preceding 4 weeks. And because the group they surveyed was so large, they could generalize these findings to the entire population of British 16- to 44-year-olds. Had they conducted two case studies instead, one male and one female, and generalized in the same manner, they would have had to state that all men or all women between the ages of 16 and 44 have masturbated at least once, or that none of them have. Either conclusion would have been highly misleading. (See Psychology in the News: Social Media in Psychological Research.)

Psychology in the News: Social Media in Psychological Research Social media sites such as Facebook, Twitter, MySpace, Instagram, Tumblr, and others are opening up exciting new worlds for psychological researchers—as is the possibility of using the Internet to access large samples for a variety of surveys. For example, a recent online survey of 1,000 respondents conducted over a 4-day period allowed researchers to discover quickly that the popularity of the then-political leader had plunged precipitously (Woods, 2014). A few months later, she was no longer in office.

An examination of psychology databases reveals an enormous number of recent investigations that either use the Internet and social media as sources of information, or look at the psychological implications of social media use. For example, analyses of Twitter feeds have suggested that excessive use of language associated with anger and other negative emotions may be correlated with higher rates of cardiac problems and even mortality, and that positive emotions revealed in language usage may be related to significantly better mental and physical health (Eichstaedt et al., 2015).

Csepeli and Nagyfi (2014) used analyses of Facebook entries to explore the mental states of users. Their analysis suggests the possibility of developing media-based methods for identifying persons with mental problems.

A study of 261 adolescent and young adult Facebook users indicates that users who have clearly defined notions of personal identity are more likely to present their true selves than those with a less coherent sense of self. The latter are more likely to present a false image of self (Michikyan, Dennis, & Subrahmanyam, 2015). Reassuringly, other research suggests that false information presented in a Twitter format is less likely to be believed than identical false information presented in a different format (Fenn, Griffin, Uitvlugt, & Ravizza, 2014).

(continued)

JGI/Jamie Grill/Blend Images/Getty Images ሁ The widespread use of social media

provides researchers with ready access to the thoughts, beliefs, and activities of large groups of people. But what do these public presentations of self actually mean? How much do they reveal of the real self ?

Section 1.5Sources of Psychological Information

Psychology in the News: Social Media in Psychological Research (continued) To Think About

One of the advantages of using social media for psychological research is that it opens up an enormous pool of potential participants, and it allows researchers to observe how people behave in their private lives. In these media, users leave permanent, electronic traces that, in the hands of a skillful researcher, might lead to important new insights about human behavior. It also suggests the possibility of discovering persons who have been “radicalized” by terror-oriented groups or who are susceptible to radicalization. But social media, along with the possibility of monitoring almost all digital communication worldwide, also make possible what Marsden (2014) describes as “the biggest government surveillance program mankind has ever known” (p. C16). Do you think issues of privacy and confidentiality might be involved in research based on social media? What factors can you think of that might affect the reliability of online surveys?

To Do

Research and clarify the issue of cyber spying in this new, terror-threatened age.

Correlational Research A great deal of psychological research is intended to find out whether a relationship exists between two variables (a variable is any quality or characteristic, like intelligence or success, that can vary among individuals). It might ask questions such as, “Are more intelligent people more successful than those less intelligent?” “Is hyperactivity related to parental upbringing?” “Does anxiety contribute to poor test performance?” or “Are attractive people more likely to be successful in business?”

Research designed to answer such questions often results in a measure of correlation—that is, a measure of relationship or connection—and is therefore called correlational research. Correlations are evident when a change in one variable (one measure) is accompanied by a predictable change in another related variable—hence, the label correlated.

A positive correlation exists between two variables when a change in one of the variables is reflected in a similar change in the other. That is, if one variable increases, we can expect the correlated variable to do likewise. And if the variable decreases, we would expect the corre- lated variable to decrease also. For example, many studies have shown a substantial positive correlation between intelligence and success. Higher measured intelligence is generally asso- ciated with higher measured success; similarly, lower measured intelligence is linked with lower measured success (see, for example, Strenze, 2015).

A negative correlation is observed when a change in one variable is accompanied by an opposite change in the other. That is, if one variable increases, the other would be expected to decrease; and if the first variable decreases, the negatively correlated variable would be expected to increase. For example, some research suggests a negative relationship between use of social media during a class and achievement in that class: As social media use increases, achievement tends to decrease (see, for example, Junco, 2015).

Section 1.5Sources of Psychological Information

Numerically, correlation is most often expressed as –1.00 for a perfect negative correlation, +1.00 for a perfect positive correlation, and 0 for lack of correlation (Figure 1.7).

Figure 1.7: Graphical representation of correlation ሁ Plotted data can help show the strength and direction of a correlation between two variables.

f01.07

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Section 1.5Sources of Psychological Information

It would seem logical to assume that if there is a high positive correlation between two vari- ables, one must cause the other—and that may sometimes be the case. In fact, if a variable does cause another, there will be a correlation between the two. Put another way, correlation is essential evidence of causation—but it is not sufficient evidence. The assumption that cor- relation proves causation is known as the correlation fallacy.

For example, there is a high positive correlation between children’s shoe sizes and their abil- ity to read. But it would be a correlation fallacy to conclude that having big feet helps children read. Having big feet, like being able to read, simply reflects the child’s continued develop- ment and growth. (The correlation fallacy is explained more fully in a later section.)

Experiments An experiment is a research procedure in which investigators manipulate one or more of the variables in a situation and observe the effects of this change on other variables. As the word implies, variables are characteristics that differ (vary) from one person or situation to another. A variable may be a measurement, an outcome, or some other way of describing or classifying things such as people, events, or objects. Intelligence test scores, environmental factors, physical characteristics, medications, and so on are all examples of variables.

Independent and Dependent Variables Experiments are especially powerful tools in science’s quest for knowledge because control- ling variables makes it possible to observe and measure causes and effects. The variables the experimenter controls and whose effects are being investigated are independent variables; variables that may be affected by changes in independent variables are dependent vari- ables. Independent variables are assumed to have an effect on dependent variables. Depen- dent variables are the outcomes that are ordinarily measured at the end of an experimental procedure.

As a simple illustration, an experiment can easily be designed to determine whether a new approach to teaching is better than the current approach. For example, the researcher might want to compare the effectiveness of online, distance learning with a more traditional, face- to-face, in-the-classroom approach. The experiment would require that participants be assigned to one or the other of the teaching methods, that the methods be put into practice, and that subsequent performance be measured and compared. In this case, teaching method is an independent variable; performance, a dependent variable. If teaching method affects performance, it (the independent variable) may be used to predict learning (a dependent variable). (See Figure 1.8.)

Note that most experiments can be reworded in terms of an “if-then” statement. What the investigator is saying is “if such and such, then such and such.” The if-then statement is the hypothesis (prediction) that the experiment is designed to investigate. The “if ” part of the statement usually defines the independent variable; the “then” part of the statement is the dependent variable. For example, the hypothesis that online learning will be as effective as the face-to-face approach can be reworded to “if learners complete the course online, then they will achieve as well as if they complete the face-to-face course.”

Section 1.5Sources of Psychological Information

Figure 1.8: Illustration of an experimental design ሁ A simple experiment designed to test a hypothesis. Note that hypotheses can generally be

worded as “if-then” statements. The “if ” part of the statement is the independent variable (in this case, the change in teaching method); the “then” part is the dependent variable (in this case, the grades obtained by members of the experimental group). The hypothesis might be worded: If we use teaching method A, then learners will perform at a higher level.

Experimental group (Students are taught using new method A.)

Hypothesis: New teaching method A is more

effective than conventional method B for teaching Introductory Psychology.

Grades obtained by members of the experimental group are compared with those of the control group. Establish whether the scores from the experimental group are greater

than, less than, or equal to the scores from the control group.

f01.08

Control group (Students are taught with the

conventional method B.)

Collect scores for the experimental group.

Collect scores for the control group.

Students are randomly assigned to one of two groups.

Independent variable

(Teaching method)

Dependent variable

(Learning)

Section 1.5Sources of Psychological Information

Experimental and Control Groups The most common experiment is that which makes use of an experimental group—usually a group that is subjected to some treatment or procedure—and one or more control groups (sometimes called comparison groups)—typically a group highly similar to the experimental group but not subjected to the experimental treatment. For example, the conclusion that a new toothpaste leads to 40 percent fewer cavities might be based on an experiment in which some individuals brush regularly with the new product (the experimental group) while oth- ers brush with their regular toothpaste (the control group). Comparison of teeth between these two groups after the experimental procedure would enable investigators to determine the extent to which the new product prevents cavities. Cavities are a dependent variable in this experiment; toothpaste employed is an independent variable.

An experimental design that does not use comparison groups cannot be relied upon, since we have no way of determining whether outcomes might have been identical or different without any experimental treatment. However, for the control group to be useful, it must be as similar as possible to the experimental groups in all relevant ways. For example, in the toothpaste experiment, it is critical that both the experimental and the control groups have a similar incidence of cavities before the experiment.

Note that it if the results of an experiment are to be generalized (applied to a larger group), it is essential that the participants involved in the study (the sample) be representative of the larger group from which they are drawn (the population). In psychological research, a popu- lation is defined as the entire group to which experimental results are intended to apply. For example, a study of the typical vocabulary development of specific minority-group 2-year- olds might be intended to be applicable to all 2-year-old members of the minority group— that is, to the entire population of these 2-year olds. Often, however, researchers do not have access to all members of a population but must, instead, select representative individuals from the population. That is, research is usually limited to a representative sample drawn from the larger population. As we see later, one way of ensuring representativeness is to sample randomly from the general population.

Ex Post Facto Studies There is an important distinction between a true experiment and what is termed an ex post facto study. In a true experiment, the investigator assigns subjects to experimental conditions and controls independent variables. But there are many situations in which the experimenter does not have control over independent variables. For example, an experiment designed to uncover the contributions of smoking to lung cancer would require that the experimenter randomly assign participants to an experimental group who would be required to inhale cigarette smoke in a prescribed manner over a specified period of time. Other participants, comparable to the experimental group in all relevant ways, would be required not to smoke. Clearly, there are ethical reasons why this experiment cannot be carried out.

In cases such as this, investigators often conduct ex post facto studies—literally, after-the- fact studies. These are studies in which participants are selected on the basis of differences that already exist among them, in terms of either dependent or independent variables. For example, instead of assigning participants to smoking or nonsmoking groups, investigators select people who have a history of smoking or not smoking and compare them with respect to the dependent variable, cancer or no cancer. Alternatively, investigators might begin by

Section 1.5Sources of Psychological Information

looking not at independent variables (smoking or nonsmoking), but at the dependent vari- able (cancer or no cancer) and then ask, “How many of those with cancer were smokers and how many were nonsmokers?” They might also ask, “How many without cancer were smok- ers or nonsmokers?”

Ex post facto studies are highly common in psychology simply because investigators do not usually have control over many important independent variables such as social class, fam- ily composition, mother-infant interaction, where people live, whether they have pets in the home, and so on.

There is one important caution in interpreting the results of ex post facto research. Although these studies can establish the presence of relationships, they do not provide evidence that one variable causes another. An ex post facto study might establish that a relationship exists between father absence in early childhood and delinquent behavior in adolescence, but it can- not prove that father absence causes delinquency because any number of other uncontrolled variables (for example, poverty, mother absence, family size) might be causally related. Only a carefully controlled experiment can provide sufficient evidence of causation.

For a comparison of research methods that differ in terms of who is observed, when, and how, see Table 1.2.

Table 1.2: Common types of psychological investigations

Method Description Who is observed When they’re observed

How they’re observed

Case study An in-depth investigation

of a single individual (or unit)

over a longer period of time

using a variety of approaches

Survey A descriptive study of a representative sample

at one point in time

using questionnaires, examinations, tests, and other forms of observation

Longitudinal study

A focused investigation

involving an individual or a group of individuals

over a defined period of time

using any of a variety of data-gathering approaches

Cross-sectional study

A focused investigation

involving groups of individuals

at one point in time

using one or more of various investigative approaches

Experimental study

A study in which the investigator controls important variables

and assigns participants to groups

as dictated by the experimental design

adhering to the principles of carefully controlled scientific experimentation

(continued)

Section 1.6Interpreting Psychological Research

Method Description Who is observed When they’re observed

How they’re observed

Ex post facto study

A controlled investigation in which the investigator selects participants

but has no control over their assignment to groups

so is forced to use groups and individuals made available by their circumstances

using the principles of science limited by the need to use convenient and available samples

Descriptive study

A study undertaken to describe the characteristics of what is being investigated

often involving groups or sometimes individuals

usually studied at one point in time, but occasionally over a time span

using existing records (archival) or based on surveys, interviews, or case studies; longitudinal or cross-sectional research; or correlational studies

1.6 Interpreting Psychological Research To what extent can we rely on an experiment such as the toothpaste study described earlier, assuming, of course, that the results were reported accurately? Should we all run and pur- chase armloads of the new toothpaste?

Would the results be affected, for example, if the control group had been selected from a small rural area where the drinking water is obtained from a questionably clean river whereas the experimental group members reside in an urban area where fluoride is added to the water? Would the results be affected if the dentists who examined the subjects were shareholders in the company that manufactures the new toothpaste and if they knew who was a member of the experimental group and who belonged to the control group? Is it important to know the number of cavities in the histories of members of each of these groups?

These questions touch on various potential weaknesses of psychological research including experimenter bias, subject bias, sampling bias, and the correlation fallacy.

Experimenter Bias An assortment of rats was divided among two groups of psychology students (Rosenthal & Fode, 1963). The students knew that psychologists had been successful in breeding strains of rats highly different in their ability to learn how to run through mazes—so-called maze-bright and maze-dull rats. In this experiment, one group of students was told that they had been given rats of the maze-bright variety; the second group had to be content with less intelligent rats. In fact, however, both groups received randomly assigned rats of presumably equal intellect.

Students were asked to work with these rats over a period of time and to train them in maze tasks. Amazingly, students who had been led to believe that they had bright rats reported considerably more success in training their rats. In addition, they thought the rats more

Table 1.2: Common types of psychological investigations (continued)

Section 1.6Interpreting Psychological Research

cooperative, gentler, and generally more pleasant to work with than did students whose rats were labeled “dull.”

This experiment was among the first of many that have illustrated what is termed experi- menter bias. It appears that the expectations of experimenters exert subtle and sometimes remarkable influences on their actual observations. Note, however, that experimenter bias should not be confused with experimenter dishonesty. Bias is an unconscious effect; dishon- esty is clearly more deliberate.

A similar investigation conducted with elementary school children also illustrates experi- menter bias (Rosenthal & Jacobsen, 1968). It involved telling teachers that some of their stu- dents had been identified as potential “bloomers.” “Bloomers” were described as students of average or below-average achievement whose potential indicated they could easily achieve at a much higher level. The experimenters led the teachers to believe that they had developed a test that enabled them to identify these students and casually let them see a list of these “bloomers.” Astonishingly, although the “bloomers” had been randomly selected, they per- formed better than other equally intelligent students.

There have been many replications of this investigation since 1968. Some have not supported the original findings (Wineburg, 1987), but many have, although not always with results quite so dramatic (Jacobs & Harvey, 2010; Rubie-Davies, 2010). It seems clear that on occasion the expectations of teachers can affect not only the achievement of their students, but also their performance on objective measures of intelligence as well as their general behavior.

One of the most effective and most common means of guarding against the influence of exper- imenter expectations is to ensure that those responsible for gathering crucial experimental data not know which subjects are in the experimental groups and which are in the control groups. In the toothpaste experiment described earlier, if the dentists examining the children did not know which children had brushed with the new toothpaste and which were members of the control group, experimenter expectations would not likely affect the conclusions of the experiment.

Studies in which neither the examiners nor the subjects are aware of who is in the experi- mental group are termed double-blind procedures. In a single-blind procedure either the subject or the examiner is unaware (“blind”). For example, in an investigation of the effective- ness of a new drug, some participants might be given the real drug; others would receive an innocuous substitute (a placebo). In a single-blind procedure, patients would be unaware of which drug they were being administered. In a double-blind procedure, neither the examin- ing physicians nor the participants would know who received the placebo and who received the experimental drug.

Subject Bias Several decades ago in the Hawthorne plant of the Western Electric Company in Chicago, two psychologists experimented with different ways of increasing productivity among a group of female workers (Roethlisberger & Dickson, 1939). In successive experiments the women were asked to work for longer periods of time, for shorter periods of time, for long periods with short rest breaks, for short periods with long rest breaks, with bright illumination, with low lighting, with lights turned almost off, with bonuses, without bonuses, and so on. Strangely, it did not matter what the experimenters did: Production always seemed to increase.

Section 1.6Interpreting Psychological Research

More recent research has shown that this so-called Hawthorne effect is not always apparent or very significant (Chiesa & Hobbs, 2008). Nevertheless, the possibility that the outcome of an experiment may be affected by the fact that subjects know they are subjects still exists and must be guarded against. Participants are often anxious to please investigators; consequently, their responses may sometimes be misleading. To guard against this possibility, subjects are often not told whether they are members of an experimental group (a single-blind procedure).

Sampling Bias One of the most common weaknesses of many experiments has to do with inappropriate or biased sampling. Two crucial criteria should be met when selecting members of experimen- tal and control groups. (A criterion is a necessary condition, a standard for judgment.) First, the subjects must represent the group to which the experimenters wish to generalize. Second, the experimental and control groups must be as similar as possible on all relevant variables at the beginning of the experiment.

If the experimental group is significantly different from other groups, then the experiment will not provide information that can be generalized to other groups. Consider, for example, an experiment designed to compare the effectiveness of two teaching methods. If the experi- menter intends to determine the relative effectiveness of these methods for the entire popula- tion of students in a given school system, it is important that experimental and control groups be as similar as possible to that population in terms of intelligence, achievement, motivation, and other relevant variables. If subjects are selected from a single school where students have higher intelligence test scores, the results of the experiment might not be valid for students in other schools.

Problems regarding the representativeness of samples are most evident in large-scale sur- veys where the intention is to generalize to an entire population. Political forecasts would be highly unreliable if only one segment of the population were sampled. For example, it would be difficult to predict how a nation would vote if forecasts were based only on surveys of

academic populations or truck drivers or hermits.

To ensure that the results of such a survey apply to the entire population, investigators might select their sample so that it matches the population in terms of as many relevant characteristics as possible—a process called stratified sampling. If 52 percent of the population is female, close to 52 percent of the sample should also be female; if 23 percent have college degrees, then about 23 percent of the sample should also have col- lege degrees. Similarly, in an ideal situation, the sample must match the general popula- tion in terms of age, religion, socioeconomic background, geographic location, and so on. Perhaps it even needs to include a handful of hermits.

TongRo Images/Thinkstock ሁ No matter how large the sample, if its

characteristics are very different from those of the population, resulting conclusions will not have general validity. This soccer crowd, for example, might be very different from the mass of humanity who stayed home.

Section 1.6Interpreting Psychological Research

The most common way to ensure that experimental groups are representative of a larger population is to use random sampling. Sampling is random when all members of the popula- tion have an equal chance of being selected. When this is the case, if enough representatives are drawn from the population, there is a high probability that the experimental group’s char- acteristics will be very similar to those of the entire population. If 23 percent of a population is male and 77 percent female, a large enough sample drawn randomly from this population should be close to 23 percent male and 77 percent female. By the same token, the sample should resemble the entire population in terms of average intelligence, racial background, and other variables that might be important. In most cases, after the sample has been selected, experimenters can make sure that it is a representative sample by comparing it to the popula- tion on important variables.

Unfortunately, random and stratified sampling are possible only when investigators have access to the entire population to which they want to generalize. In many cases, circumstances dictate that samples will be samples of convenience. For example, those who do research on aging seldom have access to a random or stratified sample of the entire aging population. Instead, they are often limited to members of clubs, religious groups, or residents of care facilities. Generalizing from these convenient samples requires caution.

The need for comparability of experimental and control groups, and for representativeness of samples, is obvious in the toothpaste experiment. Suppose, for example, that the control group averaged 30 percent more cavities than the experimental group at the beginning of the experiment: Regardless of the effects of the new toothpaste, it would be reasonable to expect that the rate at which the children developed cavities would be higher among those who initially had more cavities. Similarly, if all children in the study were selected from a sin- gle area where dental care was exceptionally good—or exceptionally bad—the sample might be totally unrepresentative of a more general population. Deliberately or accidentally biased sampling can easily ensure that the results of an experiment will be totally invalid.

The Correlation Fallacy As mentioned earlier, another pitfall in psychological research relates to the correlation fal- lacy—the belief that if two variables are correlated, one must cause the other. There are at least two reasons why correlation cannot be used to justify cause-and-effect conclusions. One is that a correlation between A and B does not, by itself, provide evidence of the direction of causality. That is, even if the correlation reflected causation, we might not know whether A causes B or B causes A. For example, depression and sleeping problems are often positively correlated (National Sleep Foundation, 2015). But this correlation does not establish whether depression leads to sleeping problems or whether sleeping problems might be one of the causes of depression.

Second, a correlation between A and B does not answer the question of whether the reason for the correlation might be the result of a third variable, C. In the example just given, both the sleeping problems and the depression might be the result of a variety of other variables such as stress in family relationships, school-related problems, medical problems, chemical imbalances, head trauma, and so on.

The correlation fallacy is well illustrated by the observation that an investigation of people ranging in age from 2 to 22 would probably reveal a high correlation between finger length

Section 1.6Interpreting Psychological Research

and the ability to understand concepts in advanced calculus. That, of course, would not prove that having long fingers helps people understand calculus—nor that understanding calculus leads to an increase in finger length. Rather, it likely reflects the effects of a third group of variables related to changes that occur over time.

Other Problems of Psychological Research Among other problems that face research- ers, as well as those of us who look for truth among their conclusions, are those of hon- esty, memory distortion, and inadvertent conceptual distortion. Studies of drug use, for example, have often provided incon- clusive and contradictory results, probably largely because admitting to drug use is

often equivalent to confessing to a crime. In studies such as these, the dishonesty of partici- pants is a crucial factor that can do much to invalidate the results of research.

Related to the problem of subject honesty is that of having to rely on imperfect memories. Child development psychologists have had some difficulty establishing conclusively the aver- age age at which children learn to walk, a problem often related directly to the memories of their mothers. Unless the researcher is present whenever significant developmental events occur, or unless these events can be recorded objectively, reliance must be placed on the par- ticipant’s memory or on that of someone else who observed the event in question. In either case, it is often wise to question the accuracy of results that are not obtained through direct observation.

Research Ethics The use of both human and animal participants in psychological research is an emotional and controversial topic. It raises important ethical issues relating to how participants in experiments are treated. Many of the procedures used in earlier investigations—where, for example, animals were euthanized or human participants were deceived, coerced, or other- wise made to do things they would not ordinarily do—are no longer acceptable. Some people believe that under no circumstances should animals be harmed in the interests of science (A. Knight, 2008); others argue that when the potential benefits are sufficiently important, ani- mals might need to be sacrificed (Brody, 2001).

The American Psychological Association provides guidelines for the ethical treatment of ani- mal and human participants in research (APA, 2014b, 2014c). With respect to animal research, these guidelines stipulate that the research must have clear, scientific purpose with positive potential benefits, that animal care must comply with strict regulations, and that every effort must be made to minimize animal pain and suffering.

iStock/Thinkstock ሁ Because 100 percent of divorces begin with

marriage, there is a high correlation between number of weddings and number of divorces. But it would be meaningless to say that weddings are an important cause of divorces—or vice versa. Such reasoning illustrates the correlation fallacy.

Section 1.8The Relevance of Psychology

With respect to research with human participants, guidelines require that the ethical accept- ability of the research be reviewed; that all participants be made fully aware of all aspects of the research that might affect their willingness to participate; that they be completely free not to take part; and that participants be protected from physical and mental danger or discomfort.

Avoiding the Pitfalls Have you by now developed an image of psychological researchers stumbling blindly among the numerous pitfalls of scientific research, never knowing for certain what to believe? That image would be misleading: Well-trained researchers are usually acutely aware of potential pitfalls; they can guard against falling into traps that might deceive the less wary.

1.7 Philosophical Issues and Psychological Controversy The search for explanations of human behavior is based on a number of assumptions that direct that search and that—in a very real sense—validate many of the beliefs resulting from the search. The most basic of these assumptions are philosophical in origin, have been sub- jects of controversy and debate that continue unresolved to this date, and cannot be tested or examined completely objectively. If they could, they would not be assumptions (which are, by definition, unproven) but would be laws or principles (beliefs more firmly grounded in objec- tive observation).

Most important among these assumptions are those that deal with human nature and with the causes of behavior: Is behavior a function of free will, or is it determined by other forces? Are mind and body separate? Is behavior determined by underlying characteristics in the person (termed dispositions), or is it determined by the immediate situation?

Depending on the assumptions they make, some psychologists believe we exercise deliberate control over our behavior; others are primarily deterministic: They believe behavior is an inevitable consequence of identifiable causes. Some look for the causes of behavior among genetic factors; others attribute a greater role to environmental forces. The end result of the different assumptions psychologists make is that psychology is characterized by a number of different theories.

Psychology is a science that is sometimes gray rather than always black or white. Not all the pieces of the puzzle have yet been discovered or assembled.

1.8 The Relevance of Psychology What do you want out of psychology? The question is not as simple as it might be in other fields. A bookkeeping course might teach you how to keep books; a course in dentistry, how to be a dentist; and a course in mathematics, how to do mathematics. But a course in psychol- ogy is not likely to teach you how to do psychology. Besides, what is involved in “doing” psy- chology is not at all clear. Clinical psychologists “do” psychology in one sense: They attempt to apply what they have learned or discovered to alleviate mental and emotional problems. Experimental psychologists also “do” psychology, but the things they do clearly differ from

Section 1.9This Book

the things done by clinical psychologists. A college professor “does” psychology; but that too is different. In any case, you will probably not do any of these things as a result of this one course.

What then? Is psychology going to reveal the grand mysteries of the human psyche, expand- ing your understanding of yourself and of humanity? Will it enable you to function better as a human being, directing you along paths of growth and happiness?

To some extent, yes. After all, psychology has enormous applications in a tremendous variety of areas. The insights gained by studying psychology can make you a better parent, a more memorable teacher, or a startlingly effective salesperson. Psychology can help you under- stand why you feel and act as you do, how your friends and family affect your behavior, or why you are moved to do certain things and do your utmost to avoid others. Advances in our knowledge of brain structures and functions suggest new approaches for treating addictions; increased understanding of how our sensory systems work has led to more effective treat- ments for sensory problems. Psychology gives us insights into how memory can be improved and maintained as we age. And it suggests highly effective ways of dealing with mental and emotional disorders.

1.9 This Book In a very real sense, the remaining chapters of this book are a definition of psychology. That definition takes the form of a division of psychological topics into chapters, each dealing with a different facet of human behavior, and each attempting to summarize and interpret what is known about that aspect of behavior.

Following this introduction, we move to a consideration of our biological aspects: the brain and how it relates to consciousness (Chapter 2), and sensory systems and perception (Chapter 3). Chapter 4 looks at the forces underlying the changes that occur between birth and maturity, and Chapter 5 examines learning, language, and cognition. Chapter 6 is concerned with memory and intelligence. In Chapter 7, we look at motivation and at the effects of stress and emotions on our behav- ior and on our mental and physical well-being. Chapter 8 explores social psychology: how we relate to each other, how and why we fight and love. Chapter 9 exam- ines human personality—the qualities that make each of us absolutely unique. Finally, Chapter 10 looks at mental disorders and the therapies that psychology provides for righting these disorders. The breadth and substance of psychology are evident in this arrange- ment of topics; and its definition, too, is implicit in them. That definition can be summarized in a single outline, as in Table 1.3, or can be reduced even further to a state- ment that bears repeating: Psychology is the science that studies human behavior and mental processes.

Gary Waters/Ikon Images/Getty Images ሁ It’s a complex puzzle psychology

is working on. And not all the pieces have yet been found.

Chapter Summary

Table 1.3: An outline of this text as a definition of psychology

Chapter Definition

1: The Science of Psychology Psychology is the science that studies human behavior and mental processes.

2: The Brain and Consciousness It looks at the physiological basis of behavior and at our different states of consciousness.

3: Sensation and Perception It examines our sensory and perceptual systems, which are our sources of contact with the external and internal world.

4: Human Development It is concerned with the significant changes that transpire between birth and death, and with the forces that drive these changes.

5: Learning, Language, and Cognition It asks how we learn and know.

6: Memory and Intelligence It investigates how we remember, and it studies the intellectual processes that our intelligence makes possible.

7: Motivation, Emotions, and Health It looks at the reasons for our behavior—at our motives—and it asks how stress and emotions affect our physical and mental health.

8: Social Psychology It looks at relationships among individuals and at the enormous power of social influences.

9: Personality It examines human individuality and tries to understand how each of us is different and unique—and at the same time, how we share certain characteristics that define our humanity.

10: Psychological Disorders and Therapies And it tries to understand mental and emotional disorders and searches for therapies to alleviate them.

Even though our consideration of human behavior and thinking—the subject of psychol- ogy—is divided into separate topics, in the end, it is less the individual topics in which we are interested than the whole. We should not lose sight of this fact: The puzzle that psychology is gnawing at involves the entire person.

Chapter Summary 1.1 What Is Psychology? Psychology is concerned with all that affects human behavior, thought, and emotion: It is the science that studies behavior and mental processes. About 40 percent of all psychologists are clinical psychologists. The other 53 divisions include counsel- ing, industrial/organizational, school, educational, developmental, clinical, social, personality, and experimental.

1.2 Early Origins of Psychology: Psychology had its origins in Greek philosophy (psyche is Greek for “soul”; logos, for “study”), was profoundly affected by medical discoveries, and borrowed its scientific methodology from Newtonian physics. Its more recent origins date to Wundt’s psychological laboratory (1879) and his followers, who established the structuralist school, followed by William James’s functionalism.

Chapter Summary

1.3 Current Approaches to Psychology: Psychology, especially in North America, was strongly influenced by Watson and Skinner’s rejection of earlier, more mentalistic approaches and their championing of behaviorism. Current approaches also include Freud’s psychody- namics, the continuing influences of cognitivism and humanism, sociocultural approaches, and biopsychosocial approaches that look at the combined influence of biological, psychological, and social factors.

1.4 Psychology as a Science: Science is an attitude that insists on precision and replicabil- ity. It is also a collection of methods designed to maximize the validity of conclusions. Five steps of the scientific method are (1) ask a question; (2) develop a hypothesis; (3) collect rel- evant observations; (4) analyze observations to test the hypothesis; and (5) reach and share conclusions.

1.5 Sources of Psychological Information: Observation is the source of knowledge in all sciences. Psychological investigations can be descriptive (describing characteristics of indi- viduals or groups) or more experimental or correlational. Longitudinal studies look at the same individual(s) at different times; cross-sectional studies look at different individuals at the same point in time. Descriptive research can be based on observation that occurs in natu- ral surroundings (naturalistic) or in more contrived environments such as laboratories. It can be based on observations of a single individual or unit (a case study) or of larger groups (a survey). Correlational studies try to discover relationships between variables but cannot prove causation (the correlation fallacy). Experiments allow investigators to manipulate independent variables to determine their effects on dependent variables. In an ex post facto study, investigators do not assign participants to groups and do not manipulate independent variables.

1.6 Interpreting Psychological Research: Single-blind and double-blind procedures (in which the examiners, the subjects, or both do not know who are members of the experimental group) safeguard against experimenter and subject bias. To be able to generalize findings, the experimenter must study a sample representative of the population to which generalizations are to be made (often randomly selected for that reason). Psychological research can also be affected by problems of subject dishonesty, memory distortions, conceptual confusion, and the tendency to assume that if two events are correlated, one must have caused the other.

1.7 Philosophical Issues and Psychological Controversy: Psychological research is based on a number of sometimes controversial assumptions (nature vs. nurture, determinism vs. free will). The end result is a variety of different theories and beliefs about human behavior.

1.8 The Relevance of Psychology: The primary goals of psychology are to explain human behavior, to make increasingly accurate predictions, and to achieve a greater degree of effec- tiveness in alleviating human distress and in enhancing the joyful aspects of living. Not all the pieces of the puzzle have yet been discovered or assembled.

1.9 This Book: This book is a multichapter definition and exploration of psychology.

Key Terms Archival research Describes research that relies on preexisting records such as census counts, birth records, and school achieve- ment records.

Assumption A belief that guides reason- ing and research, accepted as fact, but often unprovable.

Chapter Summary

Average A mathematical indication of central tendency, obtained by summing the numbers that describe a characteristic and dividing by the number of cases involved. Although averages are often good descrip- tions of the characteristics of a group, they typically do not describe individuals well.

Behaviorism A general term for approaches to psychology concerned pri- marily with the observable components of behavior (such as stimuli and responses).

Biopsychosocial model A broad approach in psychology that looks at the combined influence of biological, psychological, and social factors especially as they relate to human health and wellness.

Bubba psychology An expression for folk beliefs in psychology; also referred to as naïve or implicit theories. Bubba means “grandmother.”

Case studies A method of observation that involves the intensive examination of a single subject or unit.

Clinical psychologists Trained psycholo- gists specializing in helping people with emotional and behavioral problems. (See counseling psychologists.)

Cognitivism A general term for approaches to learning concerned with intellectual events such as problem solving, information processing, thinking, and imagining.

Control group In an experiment, a group comprising individuals as similar to the experimental group as possible except that they are not exposed to an experimental treatment. (See experimental group.)

Correlation A statistical relationship between variables. High positive correlation means that high scores on one variable are generally accompanied by high scores on the second. A high negative correlation means that high scores on one variable are typically associated with low scores on the second.

Correlation fallacy The mistaken belief that if two variables are correlated, they must be causally related. Correlation is not proof of causation.

Correlational research Research designed to uncover relationships between variables without determining cause and effect.

Counseling psychologists Psychologists whose main function is to counsel individu- als regarding issues relating to vocational or educational choices; learning prob- lems; relationships; and mild emotional, physical, and mental disorders. (See clinical psychologists.)

Criterion (plural criteria) A standard, value, or goal by which something is judged; a nec- essary condition.

Cross-sectional study Method of investiga- tion that involves observing and comparing different subjects, usually at different age levels.

Dependent variable The variable (mea- surement, outcome, behavior) that reflects the assumed effects of manipulations of the independent variable(s) in an experi- ment. The “then” part of the if-then equation implicit in an experimental hypothesis. (See independent variable.)

Descriptive research Describes the char- acteristics of an individual or of a group. Designed to answer one or more ques- tions relating to who, what, where, when, and how.

Deterministic Having to do with the belief that every action has an identifiable cause that can be predicted given sufficient knowl- edge about prior events and their effects. Often contrasted with belief in free will.

Developmental psychologists Psycholo- gists who study cognitive, physical, and emotional changes that occur between con- ception and death.

Chapter Summary

Double-blind procedure An experimental procedure in which neither the subjects nor the examiners know who is in the experi- mental group and who is in the control group.

Educational psychologists Psychologists concerned with issues relating to under- standing and improving teaching and learn- ing in educational settings.

Evolutionary psychology An approach in psychology defined by its attention to biol- ogy and genetics as sources of explanation for human learning and behavior.

Ex post facto study A study in which the experimenter does not assign subjects to experimental conditions or exercise control over these conditions; the experimenter simply studies participants on the basis of differences that already exist among them.

Experiment A research procedure in which investigators manipulate one or more of the variables in a situation and observe the effects of this change on other variables.

Experimental group In an experiment, the group of participants who are exposed to a treatment. (See control group.)

Experimental psychologists Psycholo- gists whose primary interests and activities have to do with the development and use of experimental (scientifically controlled) research.

Experimenter bias An unconscious phe- nomenon whereby experimenters’ expecta- tions influence their observations. Not to be confused with experimenter dishonesty.

Functionalism An early American move- ment in psychology associated with William James. In contrast to structuralism, it urged that psychology look at the purpose of men- tal activity rather than at its structure. (See structuralism.)

Generalization To engage in a process whereby conclusions derived under one set of circumstances are extended to other similar circumstances. The objective of most scientific investigations is to arrive at con- clusions that can be generalized.

Genomics The discipline that studies genomes in an attempt to establish relation- ships between genes and characteristics.

Hawthorne effect Describes the observa- tion that individuals who are aware that they are members of an experimental group sometimes perform better simply for that reason.

Humanism A philosophical and psychologi- cal orientation concerned primarily with our worth as individuals and with those pro- cesses that are considered to make us more human.

Humanistic psychology A branch of psy- chology whose primary concern is with the development of the self and with the unique- ness of the individual. Sometimes referred to as third force psychology; the other two forces are behaviorism and Freudian theory. (See humanism.)

Hypothesis An educated guess, often based on theory, that can be tested. A prediction based on partial evidence of some effect, process, or phenomenon, which must then be verified experimentally.

Independent variable The variable that is manipulated in an experiment to see if it causes changes in the dependent variable. The “if ” part of the if-then equation implicit in an experiment. (See dependent variable.)

Industrial/organizational psychologists Pyschologists concerned with applying psy- chological principles to workplace-related issues.

Introspection A once-popular method of psychological investigation involving careful self-examination followed by an attempt to

Chapter Summary

arrive at laws and principles that explain the introspector’s own behavior and that can be generalized to others.

Longitudinal study A psychological inves- tigation in which the same subjects are examined over a period of time.

Naturalistic observation An observa- tion that takes place in naturally occurring circumstances or environments rather than in contrived environments, and where the phenomena being observed are not affected by the observer.

Neuroscience A biologically based science that looks at the nervous system—especially the brain—to understand consciousness and higher mental processes.

Nonnaturalistic observation Observations that occur in a laboratory or in other circum- stances where the investigator deliberately manipulates or otherwise affects the phe- nomena being observed.

Philosophy The pursuit of wisdom; the study of reality in an attempt to arrive at an accurate and unified conception of the universe and its nature. Because people are part of the universe, philosophy originally included attempts to understand humans.

Pop psychology Popular psychology purportedly based on scientific psychology, widely popularized in media-based counsel- ing and analysis, but generally considered to be pseudoscience and pseudopsychology.

Population In an experiment, the group to which results are to be generalized.

Psychiatrists Medical doctors with exten- sive additional training in the identification and treatment of mental and emotional disorders.

Psychoanalysis An approach to psycho- therapy developed by Freud, based on the notion that emotional disorders result from unconscious conflicts and impulses.

Psychodynamic Relating to conscious and unconscious forces that influence behavior and personality.

Psychology The science that examines human behavior and mental processes.

Random sampling A sampling procedure in which each member of the population has an equal chance of being selected for the sample.

Sample A subset of a population. A group with characteristics similar to those of the larger group from which they are selected.

School psychologists Psychologists who deal with behavioral and learning problems affecting school children and issues relating to testing and placement of gifted or chal- lenged children.

Science An approach and an attitude toward the search for knowledge that emphasize objectivity, precision, and replicability.

Scientific method A method of inquiry involving a number of objective, logical steps designed to test the tenability of a scientific hypothesis. (See hypothesis.)

Significant In research, refers to findings that would not be expected to occur by chance alone more than a small percent- age (for example, 5 percent or 1 percent) of the time.

Single-blind procedure An experimental procedure in which either the investigators or the participants are not aware of who are members of the experimental group and who are members of the control group.

Sociocultural perspective An emphasis in psychology that looks at the role that mem- bership in social and cultural groups plays in human behavior.

Statistical procedure A way of analyz- ing data (observations). Typically used

Chapter Summary

in scientific investigations to determine whether a set of observations might have been expected to occur by chance.

Stimulus (plural stimuli) A physical stimu- lus is any change in the physical environ- ment capable of exciting a sense organ. Stimuli can also be internal events such as glandular secretions or even thoughts.

Stratified sampling A sampling procedure that takes steps to ensure that subgroups of the population are represented proportion- ally in the final sample.

Structuralism The first “school” in psy- chology, associated with Wilhelm Wundt, based on the notion that the mind can best be understood by analyzing its elements (looking at its component structures) using introspection. Studied such “elements” of consciousness as sensations, feelings, and images. (See functionalism.)

Survey A research method that involves sampling a large group of individuals.

Synesthesia A condition in which different sensations overlap and are processed simul- taneously. A person with synesthesia might see a musical note or hear a color.

Theory A body of information pertaining to a specific topic; a set of explanations for related phenomena that allows the investi- gator to make predictions (hypotheses).

Third force psychology Maslow’s term for the humanistic movement in psychology—so labeled to differentiate it from the first force (behaviorism) and the second force (Freud- ian psychodynamic theory).

Variable A property, measurement, or characteristic that can vary from one situ- ation to another. In psychological investi- gations, qualities such as intelligence, sex, personality, age, and so on can be important variables.