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Chapter 10 Biosocial Approaches

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In February 1991, Stephen Mobley walked into a Domino’s Pizza store in Georgia to rob it. After getting the money, Mobley forced store manager John Collins onto his knees and shot him execution style. Mobley was apprehended by Atlanta police after committing several other robberies and bragging to friends about Collins’s murder. He was subsequently charged with aggravated murder and sentenced to death. In the automatic appeal to the Georgia Supreme Court to get his sentence commuted to life in prison, his primary defense boiled down to claiming that his “genes made me do it.” In support of this defense, Mobley’s lawyers pointed to a Dutch study of an extended family in which for generations many of the men had histories of unprovoked violence. The researchers took DNA samples from 24 male members of the family and found that those with violent records had a marker for a mutant or variation of a gene for the manufacture of monoamine oxidase A (MAOA), an enzyme that regulates a lot of brain chemicals. Mobley’s lawyers found a similar pattern of violent behavior and criminal convictions among his male relatives across the generations and requested the court for funds to conduct genetic tests on Mobley to see if he had the same genetic variant.

The court wisely denied the defense motion. Even if it were found that Mobley had the same genetic variant, it would not show that he lacked the substantial capacity to appreciate the wrongfulness of his acts or to conform to the requirements of the law. Mobley’s lawyers were hoping to mitigate his sentence by appealing to a sort of genetic determinism that simply does not exist. As we will see in this chapter, genes don’t “make” us do anything; they simply bias us in one direction rather than another. Except in cases of extreme mental disease or defect, we are always legally and morally responsible for our behavior. Cases such as Mobley’s underline the urgent need for criminologists to understand the role of genes in human behavior as that role is understood by geneticists.

Learning Objectives ❖ Understand that while all behavior is the result of genes interacting with environments, there is no gene “for” crime ❖ Explain the basis of heritability and what it tells us ❖ Be able to explain gene–environment correlation and interaction ❖ Understand the basic ideas behind an evolutionary view of criminality ❖ Differentiate between mating and parenting effort and understand how each is related to the probability of criminal behavior ❖ Describe how the brain “softwires” itself by experience

❖ Know the basics of reward dominance theory ❖ Understand the policy implications of biosocial criminology

The Biosocial Approach Biosocial theories have not been popular with mainstream social scientists until relatively recently because they were interpreted as a sort of “biological determinism.” This kind of thinking is much rarer today as social scientists have become more sophisticated in their thinking about the interaction of biology and the environment (Robinson, 2004). Nevertheless, there are still people who fear that “biological” theories can be used for nasty purposes, but as Bryan Vila (1994) remarks, this may be the case “only if we allow perpetuation of the ignorance that underlies these arguments” (p. 329). Bigots and hate-mongers will climb aboard any vehicle that gives their prejudices a free ride, and they have done so for centuries before genes were heard of. The bottom line, as stated by Christopher Shea (2009), is that “with study after study finding that all sorts of personal characteristics are heritable—along with behaviors shaped by those characteristics—a see-no-gene perspective is obsolete” (p. B6).

Biosocial criminologists assert that because humans have brains, genes, hormones, and an evolutionary history, they should integrate insights from the disciplines that study these things into their theories and we should dismiss naive nature versus nurture arguments in favor of nature via nurture. Any trait, characteristic, or behavior of any living thing is always the result of biological factors interacting with environmental factors (Beaver, 2009; Cartwright, 2000), which is why we call modern biologically informed criminology biosocial rather than biological. Biosocial criminology is not a theory per se; rather, it is a way of looking at criminal behavior from a wide array of biologically informed theories and methodologies. John Wright and Frank Cullen (2012) view the biosocial approach as integrative and believe “biosocial criminology can lead to a criminology that is rooted more in science and empirical observations and can link criminology to a diverse array of other disciplines and research methodologies” (p. 237). These disciplines and research methodologies are contained in the developmental theories we discuss in the next chapter; this chapter sets the stage for them by outlining their foundational disciplines—genetics, neurobiology, and evolutionary psychology.

In many ways, the early positivists were biosocial in approach because they explicitly envisioned biological and environmental interaction. Their ideas and methods were primitive by today’s standards, but then so were the ideas and methods of most sciences during the 19th century. Evolutionary ideas about the behavior of all animals were poorly understood; genes were unheard of, and the brain was still a mysterious locked black box. This has all changed with the sequencing of the human genome and the advent of machines that enable us to see what is going on in the brain as we think and act. For these and other reasons, biosocial research into criminality is proceeding at an explosive pace. As Lilly, Cullen, and Ball (2007) opine, “It is clear that the time has arrived for criminologists to abandon their ideological distaste for biological theories” (p. 304).

Behavior Genetics

Behavior genetics: A branch of genetics that studies the relative contributions of heredity and environment to behavioral and personality characteristics.

Genotype: A person’s genetic makeup.

Phenotype: The observable and measurable behavioral and personality characteristics of any living thing as a result of genes interacting with the environment.

Genes: Strands of DNA that code for the amino acid sequences of proteins.

Heritability: A concept defined by a number ranging from 0 to 1 indicating the extent to which variance in a phenotypic trait in a population is due to genetic factors.

Shared environment: The environment experienced by children reared in the same family (parental SES, religion, values and attitudes, parenting style, family size, intactness of home, and neighborhood) assumed to make them similar.

Nonshared environment: That part of the environment referring to the unique experiences that make children from the same family different.

Behavior genetics studies the relative contributions of heredity and environment to behavioral and personality characteristics. The sum of the genes we get from our parents is called our genotype. Genes and environments work together to develop any observable and measurable trait —height, weight, IQ, impulsiveness, blood sugar levels, self-esteem, blood pressure, and so on—the sum of which constitutes the person’s phenotype. Genes are segments of deoxyribonucleic acid (DNA) that code for proteins. Genes simply make proteins—the stuff that builds, maintains, and replaces the tissues in your body. Although protein products such as neurotransmitters (e.g., dopamine and serotonin, discussed later in this chapter) and hormones (e.g., testosterone) have a lot to do with how we behave or feel, they do not cause us to behave or feel one way or another. They facilitate our behavior and our feelings by producing tendencies or dispositions to respond to the environments in one way rather than another. That is, they incline us; they do not compel us. Thus there are no genes “for” criminal behavior, but there are genes

that lead to particular traits, such as low empathy and impulsiveness, that increase the probability of criminal behavior when combined with certain environments.

Biosocial criminologists use twin and adoption studies to disentangle the relative influences of genes and environments, and they tell us that genes and environments are always jointly responsible for any human characteristic (Beaver, 2009; Carey, 2003). To ask whether genes or environment is most important for a given trait is just as nonsensical as asking whether height or width is most important to the area of a rectangle because without height and width together there is no rectangle. Gene expression always depends on the environment (think of identical rose seeds planted in an English garden and in the Nevada desert, and then think about where the full genetic potential of the seeds will be realized). We can think of genes as light bulbs and the environment as a dimmer switch. Just as the light from bulbs can be cranked up or dimmed down according to the requirements of the person operating the switch, genes are switched on, cranked up, dimmed down, and turned off depending on what the organism requires at the moment to meet specific environmental challenges.

Behavior geneticists quantify the extent to which genes influence a trait with a measure called heritability (symbolized as h2), which ranges from 0.0 to 1.0. The closer h2 is to 1.0, the more the variance (difference) in a trait in a population, not in an individual, is due to genetic factors. All cognitive, behavioral, and personality traits are heritable to some degree, with the traits discussed in the previous chapter such as impulsiveness and negative emotionality being in the 0.30 to 0.80 range (Carey, 2003). The most compelling evidence comes from a huge meta-analysis of 2,748 studies from 39 countries and involving almost 15 million twin pairs, which found that all 7,804 physical, psychological, and cognitive traits examined were heritable (Polderman et al., 2015). Remember, just because a trait is heritable does not mean that the environment is not involved in the development and expression of a trait. Since any differences among individuals can come from only two sources—genes and environment—heritability is also a measure of environmental effects (1 – h2 = environmental effects). Thus, in addition to furthering our understanding of the role of genes, advances in genetics have yielded enormous benefits to our understanding of the environment’s role in shaping behavior. As Baker, Bezdjian, and Raine (2006) put it, “The more we know about genetics of behavior, the more important the environment appears to be” (p. 44).

The environmental effects on a trait are divided into shared and nonshared. Shared environment refers to the environment experienced by children reared in the same family (parental socioeconomic status [SES], religion, values and attitudes, parenting style, family size, intactness of home, and neighborhood) and assumed to make them similar. Nonshared environment refers to unique environmental experiences that make children from the same family different. Nonshared environment can be familial or extrafamilial. Familial nonshared variables include gender, birth order, perinatal trauma, illness, and parental favoritism. Extrafamilial nonshared factors include having different peer groups and teachers, experiencing a different time-dependent culture, and having any other idiosyncratic experiences.

It is consistently found that shared environmental effects on cognitive and personality traits, although moderate during childhood, disappear almost completely during adulthood. This is not to say parents have no effect on children apart from the genes they provide them with. What disappear are parental effects on personality and cognitive traits that made siblings somewhat similar while they shared a home. That similarity fails to survive after the period of common rearing. The nonshared features of the environment appear to be much more salient than shared environment with respect to the formation of an individual’s personality and cognitive traits. Genetic effects on personality and cognitive traits, however, continue to increase throughout the life span (Ferguson, 2010; Gottfredson, 2011; Nisbett et al., 2012).

Gene–Environment Interaction and Correlation Gene–environment interaction and gene–environment correlation describe people’s active transactions with their environment. All living things are designed to be responsive to their environments, and gene–environment interaction and gene–environment correlation help us to understand how by showing the indirect way genes help to determine what aspects of the environment will and will not be important to us. Gene/environment interaction (G × E) involves the commonsense notion that people are differentially sensitive to identical environmental influences and will thus respond in different ways to them. For instance, a relatively fearless and impulsive person is more likely to seize opportunities to engage in antisocial behavior than a fearful and constrained person.

Gene/environment correlation (rGE) means that genotypes and environments are related. There are three types of G/E correlation: passive, evocative, and active.

Photo 10.1 The former major league baseball player José Canseco presents a fascinating case for biosocial theories. José had a fraternal twin brother, Ozzie, who also chose a career in baseball. However, in comparison with José’s 462 home runs and more than 1,400 runs batted in, Ozzie had only a “cup of coffee” in the major leagues. He came to bat only 65 times over three seasons and never hit a home run. Had he been an identical twin rather than a fraternal twin, might Ozzie have performed more like his brother? After finishing his baseball career, José wrote a book (Juiced) in which he admitted using steroids for most of his playing career.

Resolute, CC BY-SA 3.0, https://creativecommons.org/licenses/by-sa/3.0/deed.en, https://commons.wikimedia.org/wiki/File:Jose_Canseco_Pitching.png#/media/File:Jose_Canseco_Pitching.png

Gene/environment interaction: People are differentially sensitive to identical environmental influences because of their genes and will thus respond in different ways to them.

Gene/environment correlation: The notion that genotypes and the environments they find themselves in are related because parents provide children with both.

Passive rGE is the positive association between genes and their environments due to biological parents providing children with genes linked to certain traits and an environment favorable for their expression. Children born to intellectually gifted parents, for instance, are likely to receive genes that lead to above-average intelligence and an environment in which intellectual behavior is modeled and reinforced, thus setting them on a trajectory independent (passively) of anything the children have done.

Evocative rGE refers to the way others react to the individual on the basis of his or her evocative behavior. Children bring traits with them to situations that increase or decrease the probability of evoking certain kinds of responses from others. A pleasant and well-mannered child will evoke different reactions than a bad-tempered and ill-mannered child. Some children may be so resistant to socialization that parents may resort to coercive parenting or simply give up, either of which may worsen any antisocial tendencies and drive children to seek environments where their behavior is accepted. Evocative rGE thus serves to magnify phenotypic differences by funneling individuals into like-minded peer

groups (“birds of a feather flock together”).

Active rGE refers to the active seeking of environments compatible with our genetic dispositions. Active rGE becomes more pertinent as we mature and acquire the ability to take greater control of our lives. This is because within the range of possibilities available in our cultures, our genes help to determine what features of the environment will and will not be attractive to us. Active rGE ensures us that our minds and personalities are not simply products of external forces and that our choices are not just passive responses to social forces and situations. We are active agents who create our own environments just as they help to create us. Genes imply human self-determination because, after all, our genes are our genes. As Christopher Badcock (2000) put it, “Genes don’t deny human freedom; they positively guarantee it” (p. 71). Genes are constantly at our beck and call, extracting information from the environment and manufacturing the substances we need to navigate it. They are also what make us uniquely ourselves and thus resistant to environmental influences that grate against our natures. In short, genes do not constrain us, they enable us. This view of humanity is more respectful of human dignity than the blank-slate view of people as putty in the hands of environmental winds.

Figure 10.1 illustrates rGE, emphasizing that behind every gene–environment correlation, G × E is operating also. Note that there is only a one- way arrow from passive to evocative rGE, but the influence runs both ways between evocative and active rGE.

Figure 10.1 Illustrating Passive, Evocative, and Active rGE and G × E Interaction

Behavior Genetics and Criminal Behavior Although there are no behavior genetic theories of criminal behavior per se, behavior genetic studies are of immense importance in helping to better understand traditional criminological theories. For instance, in the previous chapter, we saw how different family structures predicted antisocial behavior in large studies in both the United States (Cleveland, Wiebe, van den Oord, & Rowe, 2000) and the United Kingdom (Moffitt & E-Risk Study Team, 2002). Both studies showed that genetic factors play a large part in sorting individuals into those structures. In both studies, families consisting of a divorced or never-married mother with children fathered by different men are the most at-risk family type for antisocial behavior, and families with full siblings with both biological parents present were least at risk. Genes, of course, contribute to the choices people make as well as make them easy or difficult to live with.

One of those factors influencing choices is almost certainly low self-control. As we saw in Chapter 7, Gottfredson and Hirschi (1990) attributed low self-control exclusively to parental treatment. However, there are now well over 100 studies that have shown strong links between low self-control and low levels of the neurotransmitter serotonin (Crockett, Clark, Lieberman, Tabinia, & Robbins, 2010). In other words, while we

all have to be taught to control our impulses, some of us are naturally easier to teach than others. Levels of serotonin are governed by both genes and environments; that is, genes govern the base levels of serotonin a person has and how well it is regulated, but what is going on in the environment results in serotonin levels increasing and decreasing (Wright, 2011).

In terms of differential association theory and its concern with peer effects, Cleveland, Wiebe, and Rowe (2005) found that genetic factors accounted for 64% of the variance in delinquent peer affiliation. Another study of 533 monozygotic (MZ; identical) and 558 dizygotic (DZ; fraternal) twin pairs (Button et al. 2007) found that peer group affiliation was associated with genetics and that the magnitude of the genetic effects on conduct problems increased as the level of association with delinquent peers increased. A longitudinal study of peer group deviance using data from 469 MZ and 287 DZ twin pairs followed from age 8 to 25 found that as twins matured and created their own mini-worlds (active rGE), genes played an increasingly larger role in peer choice (Kendler et al., 2007). Even molecular genetics is getting into the act. Beaver, Wright, and DeLisi (2008) demonstrated a significant effect of a gene called DAT1 (discussed more fully shortly) on peer group affiliation when controlling for a number of other risk variables.

Unlike the relatively strong genetic influences discovered for most human traits, genetic influence on antisocial behavior is modest, especially during the teenage years. Heritability coefficients for most traits related to antisocial behavior are typically in the 0.30 to 0.80 range, and for antisocial behavior itself they are in the 0.40 to 0.58 range (Ferguson, 2010; Rhee & Waldman, 2002), with h2 higher in adult populations than in juvenile populations. The reason for this is that a trait is something that may or may not be expressed according to what is going on in the environment. Crime and delinquency are the result of traits interacting with incentives and disincentives as well as how well one has learned one’s moral lessons. This, says David Lykken (1995), is why “the heritability of criminality is less than the more basic psychological traits [that are its constituent parts]” (p. 109). Strong genetic effects on antisocial behavior are most likely to be found only among chronic offenders who begin offending prior to puberty and who continue to do so across the life course (DeLisi & Conis, 2012; Moffitt & Walsh, 2003).

Molecular Genetics Heritability estimates tell us that genes are contributing to a trait, but they do not tell us which genes; only molecular genetics can tell us this. Fortunately, we can now go straight to the DNA by genotyping individuals with a simple cheek swab. We can then look at the effects of particular types of genes among individuals who have them and those who do not. As you know, we get our genes from our parents, who might both provide us with the same or different version of the same gene called an allele. For instance, you may have received a “brown” allele for eye color from your father and a “blue” allele from your mother. This tells us why even though every person has the same genes that make us human, we can still be differentiated by our alleles. If we didn’t have these differences, the police in crime scene investigation movies would not be able to identify suspects by the bodily fluids left behind at crime scenes.

Allele: An alternate form of the same gene; i.e., a “blue” allele versus a “brown” allele of the gene coding for eye color.

Genetic polymorphisms: Variations in the same gene allele (alternate form of a gene) such as SNPs and VNTRs.

Molecular genetic studies are being conducted with increasing frequency in criminology, with the huge National Longitudinal Study of Adolescent Health (Add Health) yielding some very important findings. Any individual gene accounts for only a miniscule proportion of the variance in criminal behavior, and it contributes to a trait linked to criminality, not to criminality itself, which you remember is a composite of many different traits. Genes always have indirect effects on behavior via the effects of the proteins they make on human traits and abilities.

Although we get only one allele from each parent, most genes have many allelic variations geneticists call genetic polymorphisms. Polymorphisms are differences in DNA sequences that code for the same gene but may make more or less of the substance (say, low serotonin) or affect the gene’s efficiency, which leads to slightly different functional or physical traits among individuals. Let us return to Mobley’s “my MAOA gene made me do it” argument in the opening vignette to illustrate how biosocial criminologists study the effects of these gene variants.

A major longitudinal study of maltreatment looking at the role of the MAOA gene showed why only about one-half of abused or neglected children become violent adults (Caspi et al., 2002). The MAOA gene comes in variants that geneticists call “high” and “low” activity. For a variety of reasons we cannot get into here, the low-activity version is a risk factor for a number of behavioral problems and the high-activity version is a protective factor. Neither the genetic risk nor environmental risk factors by themselves had much effect on antisocial behavior. When combined, however, the odds of having a verified arrest for a violent crime for those with both genetic (the low variant of the MAOA gene) and environmental (maltreatment) risk factors were 9.8 times greater than the odds for subjects with neither genetic nor environmental risk. Furthermore, although the low MAOA + maltreatment subjects were only 12% of the cohort, they were responsible for 44% of its criminal convictions.

Research Snippet: Alleles and Alleys This chapter discusses how inheriting certain alleles can predispose someone to an increased risk of criminal behavior. This typically occurs when these individuals are exposed to some sort of negative environmental stimulus. A large cadre of studies has found empirical support for these criminogenic gene–environment interactions examining a variety of different risk alleles across many negative environments. What if someone inherited more than one risk allele? Would inheriting additional risk alleles increase the risk of criminal behavior? One recent study investigated these questions. Barnes and Jacobs (2013) tested the additive effect of risk alleles on violent behavior by analyzing data gathered from a nationally representative longitudinal study. Genetic risk was measured by summating risk alleles of three dopamine genes. This strategy tested the idea that having more risk alleles, additively, would predict increased probabilities of violence in disadvantaged neighborhoods. The authors found that increased genetic risk impacted violent behavior more heavily when respondents lived in structurally disadvantaged neighborhoods and/or were exposed to higher rates of violent crime. In sum, the more risk alleles respondents carried, the higher the likelihood of them being violent. This effect was found to be much stronger for those living in rough neighborhoods as compared with nicer neighborhoods. Simply put, some individuals may be born into a situation with a double, triple, or quadruple whammy against them.

Barnes, J., & Jacobs, B. (2013). Genetic risk for violent behavior and environmental exposure to disadvantage and violent crime: The case for gene–environment interaction. Journal of Interpersonal Violence, 28, 92–120.

The overall conclusion arrived at by a meta-analysis of the MAOA/maltreatment research was that their interaction is a significant predictor of antisocial behavior across all studies (Kim-Cohen et al., 2006). However, a study by Widom and Brzustowicz (2006) found that while the high- activity MAOA allele buffered whites from the effects of childhood abuse and neglect as it relates to antisocial behavior later in life, it did not protect non-whites. The authors suggest that other environmental stressors, such as the high density of antisocial others in the neighborhood, may have negated the protective power of the high-activity polymorphism among non-whites. These studies all point to the importance of studying G × E interactions—how the environment modifies the effects of genes and how genes modify the effects of the environment. There are many other genetic polymorphisms related to traits associated with antisocial behavior being examined by biosocial criminologists, but we meet just one more in the section on evolutionary psychology.

The Neurosciences Whatever the source of human behavior, it is necessarily funneled through the brain, arguably the most awe-inspiring structure in the universe. Although the brain is only about 2% of body mass, it consumes 20% of the body’s energy as it perceives, evaluates, and responds to its environment (Shore, 1997). This 3-pound marvel of evolutionary design is the “chief executive officer” (CEO) of all that we think, feel, and do. Powerful brain imaging technologies such as positron emission tomography (PET), magnetic resonance imaging (MRI), and functional MRI (fMRI) have resulted in an explosion of information on the brain over the past two decades. We are a long way from fully understanding the brain, but we cannot ignore what is known about its relevance to criminology. Matt Robinson (2004) goes as far as to say that any theory of behavior “is logically incomplete if it does not discuss the role of the brain” (p. 72). As we will see, the insights criminologists can derive from neuroscience not only will buttress our theories but also may strengthen our claims for preventative environmental intervention.

Softwiring the Brain by Experience All our thoughts, feelings, emotions, and behaviors are the result of networks of billions of brain cells called neurons communicating with one another through substances called neurotransmitters. There are many transmitters and other brain chemicals, but criminologists are most interested in dopamine and serotonin. Figure 10.2 shows how neurotransmitters shunt information back and forth across the brain. Information from the environment is received from thousands of dendrites, summated in the body of the neuron, and passed on electrically down the axon. When the impulse reaches the end of the axon, it releases the neurotransmitters across the synaptic gap to further relay the message. The most important thing to remember here is that more “primitive” networks that control vital functions such as breathing and heart rate come “hardwired” at birth, but development of the higher brain areas depends a lot on environmental “software” downloaded after birth. The message neuroscience has for us is that the experiences we encounter largely determine the patterns of our neuronal connections and thus our ability to successfully navigate our lives (Quartz & Sejnowski, 1997).

Figure 10.2 Neurons, Axons, Dendrites, and the Synaptic Process

Source: Alzheimer’s Disease Education and Referral Center, 2011

Neurons: Brain cells consisting of the cell body, an axon, and a number of dendrites.

Neurotransmitters: Brain chemicals that carry messages from neuron to neuron across the synaptic gap.

Neuroscientists differentiate between two processes of brain development: experience expected and experience dependent (Schon & Silven, 2007). Experience-expected mechanisms are hardwired and reflect the history of the brain in our species. Experience-dependent mechanisms reflect the history of each person and the brain’s ability to adjust itself to the environment. An example that reflects the distinction between the two processes is language. The capacity for language is entirely genetic (a hardwired experience-expected capacity), but what language(s) a person speaks is entirely cultural (softwired in experience-dependent fashion).

Experience-expected processes have evolved as the brain’s readiness during certain critical periods for us to incorporate environmental information that is always (or almost always) present in its natural environment. Certain development processes such as sight, speech, depth perception, affectionate bonds, mobility, and sexual maturation are vital, and natural selection has provided for mechanisms designed to take advantage of experiences that occur within the normal range of human environments. The ready wired brain frames our experiences so that we will respond consistently and stereotypically to vital stimuli (Geary, 2005). If individuals experience gross departures from their so-called “species-expectable” environments, there may be many negative consequences (Twardosz & Lutzker, 2010).

Experience-dependent brain development depends on our experiences: “Experience-dependent processes are central to understanding personality as a dynamic developmental construct that involves the collaboration of genetic and environmental influences across the lifespan” (Depue & Collins, 1999, p. 507). While genes bias brain wiring patterns somewhat, most of the variability in the wiring patterns among different individuals depends on the kinds of physical, social, and cultural environments they will encounter (Gunnar & Quevedo, 2007). The brain literally wires itself in ways directly reflecting the experiences of its “owner.” Although brain plasticity is greatest during infancy and early childhood, a certain degree is maintained across the life span so that every time we experience or learn something, we shape and reshape the nervous system in ways that could never have been genetically pre-programmed (Koukkou & Lehmann, 2006).

Photo 10.2 Harkening back to the 19th century, when postmortem examinations of the brains of criminals were a frequent phenomenon, the brain of serial killer John Wayne Gacy was dissected after his execution. The attempt to locate an organic explanation of his monstrous behavior was unsuccessful.

AP Photo/M. Spencer Green

Experience-dependent wiring ensures that neural networks will be continually being made and selected for retention or elimination in “use it or lose it” fashion. Whether they are retained or not is governed by the strength and frequency of experience and is biased in favor of networks that are most stimulated during early development (Berardi, Sale, & Maffei, 2015; Restak, 2001). This is why bonding and attachment are so vital to humans and why abuse and neglect are so injurious. Hormones released by chronic stress can cause neurons to die, and children with high levels of these hormones experience cognitive and social development delays (Robinson, 2004). As Perry and Pollard (1998) point out, “Experience in adults alters the organized brain, but in infants and children it organizes the developing brain” (p. 36, italics added). Brains organized by stressful and traumatic events tend to relay events along the same brain pathways laid out by early events because pathways laid down early in life are more resistant to elimination than pathways laid down later in life. A brain organized by negative events is ripe for all

kinds of antisocial behavior.

Reward Dominance and Prefrontal Dysfunction Theories The basis of Sigmund Freud’s id, ego, and superego was the realization that if social animals are to function normally in their social groups, they must possess the ability to respond to signals of reward and punishment with the socially appropriate approach and avoidance behavior. Although our personal experiences made Freud’s model appealing, it could not be tested scientifically. Today we have a theory called reinforcement sensitivity theory (RST), which relates to how sensitive people are to rewards and punishments. This theory enables us to generate testable hypotheses relating to the pushes and pulls that Freud was concerned with and that we all feel when deciding if we should act or restrain ourselves. RST is a neurobiological theory based on the proposition that behavior is regulated by two opposing mechanisms: the behavioral activating system (BAS) and the behavioral inhibition system (BIS). The BAS is associated with the neurotransmitter dopamine and with pleasure areas in the brain (Gove & Wilmoth, 2003). The BIS is associated with serotonin and with brain structures that govern memory. Neurotransmitters such as dopamine and serotonin are the chemical messengers that shunt information between neural networks. Dopamine facilitates goal-directed behavior, and serotonin generally modulates behavior (Reuter, Cooper, Smillie, Markett, & Montag, 2015).

The BAS is sensitive to reward (just like Freud’s id) and can be likened to an accelerator motivating a person to seek rewarding stimuli. The BIS is sensitive to threats of punishment (like the superego) and can be likened to a brake that stops a person from going too far too fast. The BAS motivates us to seek whatever affords us pleasure, and the BIS tells us when we have had enough for our own good. A normal BAS combined with a faulty BIS, or vice versa, may lead to a very impulsive person with a “craving brain” that can lead him or her into all sorts of physical, social, moral, and legal difficulties by becoming addicted to pleasures such as food, gambling, sex, alcohol, and drugs (Day & Carelli, 2007). Figure 10.3 outlines the dopamine and serotonin pathways in the brain. The VTA is the ventral tegmental area where dopamine is manufactured and sent to the nucleus accumbens, the brain’s major pleasure center, as well as to the substantia nigra, another important pleasure center. The raphe nuclei are part of the reticular activating system, and their main function is to release serotonin.

Figure 10.3 Major Dopamine (light gray) and Serotonin (black) Pathways in the Brain

Source: National Institutes of Health, U.S. Department of Health and Human Services

While most of us are more or less equally sensitive to both reward and punishment, meaning that the BAS and BIS are balanced (Freud’s ego), in some people one system might dominate the other most of the time. The theory asserts that criminals, especially chronic criminals, have a dominant BAS, which tends to make them overly sensitive to reward cues and relatively insensitive to punishment cues (Day & Carelli, 2007). Reward dominance theory provides us with hard physical evidence relating to the concepts of sensation seeking, impulsiveness, and low self- control we have previously discussed since each of these traits is underlain by either a sticky accelerator (not enough dopamine, so the person engages more in the kinds of behavior that raises it) or faulty brakes (low serotonin).

Reinforcement sensitivity theory: A process that leads to the repetition and strengthening of behavior.

Behavioral activating system: A reward system associated chemically with the neurotransmitter dopamine and anatomically with pleasure areas in the limbic system.

Behavioral inhibition system: Inhibits or modulates behavior and associated with serotonin.

Reward dominance theory: A neurological theory based on the proposition that behavior is regulated by two opposing mechanisms, the behavioral activating

system (BAS) and the behavioral inhibition system (BIS).

Flight/fight system: An autonomic nervous system mechanism that mobilizes the body for action in response to threats by pumping out epinephrine.

Prefrontal cortex: Occupies about one-third of the front part of the brain’s cerebrum. It has many connections with other brain structures and plays the major integrative and supervisory roles in the brain.

A third system of behavior control is the flight/fight system (FFS) chemically controlled by epinephrine (adrenaline). The FFS is that part of the autonomic nervous system that mobilizes the body for vigorous action in response to threats by pumping out epinephrine. Fear and anxiety at the chemical level is epinephrine shouting its warning: “Attention, danger ahead; take action to avoid!” Having a weak FFS that whispers rather than shouts combined with a BAS that keeps shouting “Go get it,” and a BIS too feeble to object, is obviously very useful when pursuing all kinds of antisocial activities. You have probably noted that reward dominance theory is very similar to Freud’s notion of the battles between the id and the superego. The primary difference is that the specific brain areas and chemicals associated with approach and avoidance behavior are identified.

Another neurologically specific theory of criminal behavior is prefrontal dysfunction theory. The human prefrontal cortex (PFC) is a part of the brain located just above the eyes that occupies about one-third of the cerebral cortex and has been called “the most uniquely human of all brain structures” (Goldberg, 2001, p. 2). The PFC is responsible for things such as making moral judgments, planning, analyzing, synthesizing, and modulating emotions. The PFC provides us with knowledge about how other people see and think about us, thus moving us to adjust our behavior to consider their needs, concerns, and expectations of us. These PFC functions are collectively referred to as executive functions and are clearly involved in prosocial behavior. If these functions are compromised in some way via damage to the PFC, the result is often antisocial behavior.

PET and fMRI studies consistently find links between PFC activity and impulsive criminal behavior. A PET study comparing impulsive murderers with murderers whose crimes were planned found that the former showed significantly lower PFC and higher limbic system activity (indicative of emotional arousal) than the latter and other control subjects (Raine et al., 1998). Cauffman, Steinberg, and Piquero (2005) combined reward dominance and PFC dysfunction theories in a large-scale study of incarcerated and nonincarcerated youths in California and found that seriously delinquent offenders had slower resting heart rates and performed poorly relative to nondelinquents on various cognitive functions mediated by the PFC.

Evolutionary Psychology

The Usefulness of an Evolutionary Framework Evolutionary psychology explores human behavior using an evolutionary theoretical framework. Many disciplines such as economics, psychiatry, medicine, and political science are adopting a Darwinian framework as it has become increasingly obvious that it is extremely useful to understand the ultimate reasons why people do what they do and why things happen the way they do (Hacking, 2006). Criminologists operating within this framework explore how certain behaviors that society now calls criminal may have been adaptive. Adaptive behavior is any behavior that contributes directly or indirectly to an individual’s survival and reproductive success. These two evolutionary “goals” are common to all sexually reproducing organisms and are thus subject to the process of natural selection (Roach & Pease, 2013).

Evolutionary psychology: A way of thinking about human behavior using a Darwinian evolutionary theoretical framework.

Adaptive behavior: Any behavior that contributes directly or indirectly to an individual’s survival and reproductive success.

Evolutionary psychology complements genetics because it informs us how the genes of interest came to be present in the human gene pool in the first place. While genetics looks for what makes people different, evolutionary psychology focuses on what makes us all the same. Another basic difference is that evolutionary psychologists look at ultimate-level “why” questions (what evolutionary problem did this behavioral mechanism evolve to solve?), and geneticists look at proximate-level “how” questions (to what extent is this behavioral mechanism influenced by genes in this population at this time?). Ultimate causes are thus causes that occurred in the past that are ultimately responsible for something, whereas a proximate cause is one that is most immediately responsible for causing some observed behavioral outcome.

Theory in Action: Genetics and Neuroscience in Court: The Brian Dugan Case Brian James Dugan was born in 1956, the second of five children of James and Genevieve Dugan, both of whom were thought to have been alcoholics. Brian’s birth was evidently traumatic and may have led to brain damage. Brian was known to torture animals and set fires (he burned down his family’s garage) and was a chronic bedwetter. These three behaviors, known as the MacDonald triad, are predictive of psychopathy. Indeed, he is one of the worst psychopaths ever diagnosed with the condition, scoring 38 out of a possible 40 on the Hare Psychopathy Checklist (see Chapter 9). While still a teenager, he committed numerous assaults, burglaries, and arsons.

At the age of 28 in 1984, Dugan raped and murdered 27-year-old Donna Schnorr; in 1985, he raped and murdered 7-year-old Melissa Ackerman and raped a 21- year-old woman who survived the attack. Dugan previously attempted to abduct and rape other girls and women. He was arrested the day after Melissa’s murder. The evidence was so overwhelming that he confessed to the murders of Ackerman and Schnorr as well as that of 10-year-old Jeanine Nicarico, who had been raped and beaten to death in 1983. His confession to Nicarico’s murder was not taken seriously because two other males, Rolondo Cruz and Alejandro Hernandez, had been arrested, convicted, and sentenced to death for her murder. However, in 2002 DNA evidence conclusively linked Dugan to Nicarico’s murder, and Cruz and Hernandez were released 10 years after being convicted.

In an effort to save Dugan from the death penalty, his attorneys enlisted the help of neuroscientists to scan his brain. They found that his brain showed all the classic signs of psychopathy such as inadequate linking between the emotional and rational sides and a relatively inactive amygdala (the part of the brain that deals with emotions such as fear). Dugan’s inability to engage the emotions means that he lacked empathy, shame, and guilt and was thus callously indifferent to the suffering of others. A relatively inactive amygdala signals a relative lack of fear, which leads psychopaths to take risks most other people would not take. The jury was unimpressed with such evidence and voted to impose the death penalty on Dugan in 2009. However, the death penalty was abolished in Illinois in 2011, and his sentence was commuted to life in prison.

The Dugan case illustrates many concepts in this chapter, particularly rGE, as his genotype interacted with his abusive environment. He certainly illustrated a reward-dominant brain, being addicted to drugs, alcohol, and sex (he even molested his younger brother). The case also illustrates the value and the limitations of the genetic and neurological sciences when applied to criminal justice issues. DNA evidence served to free two innocent men from death row, and that is a truly wonderful application of science, but should DNA evidence be used to mitigate punishment (“My genes made me do it”)? Does the undisputed fact that Dugan is the worst kind of psychopath, and that we can actually determine this in terms of brain anatomy and functioning, mean that he has diminished responsibility for his actions (“My defective brain made me do it”)? Questions like these at the intersection of biosocial criminology and the law raise ethical and philosophical issues previous generations did not have to ponder.

Discussion Questions

Photo 10.3 Brian Dugan

Illinois Department of Corrections

1. Look up MacDonald triad on any search engine and discuss why childhood bedwetting, fire setting, and animal cruelty are predictors of adult psychopathy. 2. In many ways, we are our brains and our brains are us. Therefore, if our brains are not functioning normally as determined by brain scans, does that lessen

our responsibility for criminal behavior? Not that a person should be totally exonerated for having such a brain, but what about using the evidence to mitigate his or her sentence?

3. Do you agree with the jury’s decision to sentence Dugan to death?

Sources: Barnum and Gregory, 2009; Hughes, 2010

Evolutionary psychologists agree with most criminologists that although it is morally regrettable, crime is normal behavior for which everyone has the potential (Kanazawa, 2003). Evolutionary logic tells us that if criminal behavior is normal, it must have provided some evolutionary advantage for our distant ancestors. However, because modern environments are so radically different from hunter/gatherer environments, many traits selected for their adaptive value at the time might not be adaptive today. It is important to realize that it is the traits underlying criminal behavior that are the alleged adaptations, not the specific acts we call crimes (Rowe, 2002; Walsh, 2009). If behavior we now call criminal is normal, it must have conferred some evolutionary advantage on our ancestors. Judith Harris (1998) speculates about the probable traits of hunter/gatherer leaders and how they would have been useful:

Almost all the characteristics of the “born criminal” would be, in watered-down form, useful to a male in a hunter–gatherer society

and useful in his group. His lack of fear, desire for excitement, and impulsiveness made him a formidable weapon against rival groups. His aggressiveness, strength, and lack of compassion enable him to dominate his groupmates and give him first shot at hunter–gatherer perks. (pp. 299–300)

These perks were those most pertinent to survival and reproductive success—resources and women. Women would have been attracted to such men not because they were sensitive “nice guys” but rather because they had status and resources within the group and were good protectors (Buss, 2005). Such traits can certainly overshoot their optimum and become liabilities, which is often the case when exercised too freely in modern evolutionarily novel societies.

Criminal behavior is a way to acquire resources illegitimately, and the traits Harris mentions are most useful in that regard. Evolutionary scientists refer to such behavior (whether it is defined as criminal or not) as cheating and think of individual traits associated with it such as impulsiveness and aggression in terms of adaptive traits that all humans share at varying levels. Whether exploitation occurs depends on environmental triggers interacting with individual differences and environmental constraints. Although we all have the potential to exploit and deceive others, we are a highly social and cooperative species with minds forged by evolution to form cooperative relationships built on trust (Barkow, 2006). Cooperation is typically contingent on the reciprocity of others and is thus a tit-for-tat strategy favored by natural selection because of the benefits it confers. We cooperate with each other because we feel good when we do and because it identifies us as reliable and trustworthy, which confers valued social status on us.

Because cooperation occurs among groups of other cooperators, it creates niches for noncooperators to exploit others by signaling their cooperation and then failing to follow through (Roach & Pease, 2013). Criminal behavior may thus be viewed as an extreme form of defaulting on the rules of cooperation. But cheating comes at a cost, so before deciding to do so the individual must weigh the costs and benefits of cooperating versus defaulting. Cheating is rational (not to be confused with moral) when the benefits outweigh the costs. But if cheating is so rational, how did cooperation come to be predominant in social species? The answer is that cheating is rational only in circumstances of limited interaction and communication. Frequent interaction and communication breeds trust and bonding, and cheating becomes a less rational strategy because cooperators remember and retaliate against those who have cheated them. Ultimately cooperation is the most rational strategy in any social species because each player reaps in the future what he or she has sown in the past.

Yet we continue to see cheating behavior despite threats of exposure and retaliation. We do so because exposure and retaliation are threats only if cheats must operate within the same environment where their reputation is known. Cheats can move from location to location, meeting and cheating a series of others who are unaware of their reputation. This is the pattern of many career criminals who move from place to place, job to job, and relationship to relationship, leaving a trail of misery behind them before their reputation catches up. This is why cheats are more likely to prosper in large cities in modern societies than in small traditional communities where the threat of exposure and retaliation is great (Wiebe, 2012). Of course, the stability of the group and cultural dynamics must be considered. Even in communities containing large numbers of chronic criminals, there must be some level of group loyalty and cooperation.

The Evolution of Criminal Traits: Parenting Versus Mating Effort There are a number of evolutionary theories of crime (such as Anne Campbell’s “staying-alive” hypothesis discussed in Chapter 8), all of which focus on reproductive strategies. There are two ways that members of any animal species can maximize reproductive success: parenting effort and mating effort. Parenting effort is the proportion of reproductive effort invested in rearing offspring, and mating effort is that proportion allotted to acquiring sexual partners. Mating effort is associated with traits useful for committing criminal acts. David Rowe (2002) provides us with an excellent thumbnail sketch of the traits useful to mating effort, traits that can clearly be co-opted to support criminal behavior:

Parenting effort: The proportion of total reproductive effort invested in rearing offspring; traits facilitating parenting effort are associated with prosocial behavior.

Mating effort: The proportion of total reproductive effort allotted to acquiring sexual partners; traits facilitating mating effort are associated with antisocial behavior.

A strong sexual drive and attraction to novelty of new sexual partners is clearly one component of mating effort. An ability to appear charming and superficially interested in women while courting them would be useful. The emotional attachment, however, must be an insincere one, to prevent emotional bonding to a girlfriend or spouse. The cad may be aggressive, to coerce sex from partly willing partners and to deter rival men. He feels little remorse about lying or cheating. Impulsivity could be advantageous in a cad because mating decisions must be made quickly and without prolonged deliberation; the unconscious aim is many partners, not a high-quality partner. (pp. 62–63)

The reverse is also true—traits that facilitate parenting effort underlie other forms of prosocial activity: “Crime can be identified with the behaviors that tend to promote mating effort and noncrime with those that tend to promote parenting effort” (Rowe, 1996, p. 270). Because female reproductive success hinges more on parenting effort than on mating effort, females have evolved higher levels of the traits that facilitate it (e.g., empathy, altruism) and lower levels of traits unfavorable to it (e.g., aggressiveness) than males. Of course, both males and females engage in both mating and parenting strategies, and both genders follow a mixed mating strategy. It is only claimed that mating

behavior is more typical of males and parenting effort is more typical of females.

Because humans are born more dependent than any other animal, parenting effort is particularly important to our species. Humans have thus evolved to invest more in parenting effort than any other species, but there is considerable variation within the species. Gender constitutes the largest division due to different levels of obligatory parental investment between the sexes. Female parental investment necessarily requires an enormous expenditure of time and energy, but the only obligatory investment of males is the time and energy spent copulating. Reproductive success for males increases in proportion to the number of females to whom they have sexual access, and thus males have an evolved propensity to seek multiple partners. Mating effort emphasizes quantity over quality (maximizing the number of offspring rather than nurturing a few), although maximizing offspring numbers is obviously not a conscious motive of any male seeking sex. The proximate motivation is sexual pleasure, with more offspring being a natural consequence (during precontraceptive days) when the strategy proved successful.

Photo 10.4 A concentration on parenting effort is strongly associated with a prosocial lifestyle; a concentration on mating effort is strongly associated with an antisocial lifestyle.

Jack Hollingsworth/Digital Vision/Thinkstock

Reproductive success among our ancestral females rested primarily on their ability to secure mates to assist them in raising offspring in exchange for exclusive sexual access, and thus human females evolved a much more discriminating attitude about sexual behavior (Geary, 2000; Nedelec & Beaver, 2012). According to evolutionary biologists, the inherent conflict between the reckless and indiscriminate male

mating strategy and the careful and discriminating female mating strategy drove the evolution of traits such as aggressiveness and the lowering of trait levels (relative to female levels) such as empathy and constraint that help males to overcome both male competitors and female reluctance. The important point to remember is that although these traits were designed by natural selection to facilitate mating effort, they are also useful in gaining nonsexual resources via illegitimate means (Quinsey, 2002; Walsh, 2006).

Empirical research supports the notion that an excessive concentration on mating effort is linked to criminal behavior. A review of 51 studies relating number of sex partners to criminal behavior found 50 of them to be positive, and in another review of 31 studies it was found that age of onset of sexual behavior was negatively related to criminal behavior (the earlier the age of onset, the greater the criminal activity) in all 31 (Ellis & Walsh, 2000). A British cohort study found that the most antisocial 10% of males in the cohort fathered 27% of the children (Jafee, Moffitt, Caspi, & Taylor, 2003), and anthropologists tell us there are striking differences in behavior between members of cultures that emphasize either parenting or mating strategies. Cultures emphasizing mating effort the world over exhibit behaviors (e.g., low-level parental care, hypermasculinity, transient bonding) considered antisocial in Western societies (Ember & Ember, 1998).

Molecular genetic studies also find significant relationships between sexual and criminal behavior. A study by Beaver, Wright, and Walsh (2008) tested the evolutionary claim that the most antisocial males should have the largest number of sex partners. They found that the same polymorphism of the dopamine transporter gene (DAT1) that was significantly related to number of sexual partners was also significantly related to antisocial behavior. The reason for this is that one variant of the DAT1 gene is exceptionally efficient at clearing dopamine from the synaptic gap after it signals other neurons. This is problematic because it is dopamine that gives us pleasure when we engage in activities such as having sex, so if it is cleared too fast we are moved to seek more of the activity to get more pleasure (more dopamine). This constant seeking of activities to raise dopamine levels is the chemical basis of addiction to all sorts of things besides sex such as drugs, smoking, food, gambling, and alcohol (Walsh, Johnson, & Bolen, 2012). Another study of 674 males found that those who had two copies (one allele each from their mom and dad) of the same DAT1 polymorphism had significantly more sex partners (an average of 5.66) than males who had only one copy or no copies (an average of 2.94) as well as significantly higher delinquency scores and scores on other kinds of risky behaviors (Guo, Tong, & Cai, 2008). In other words, this particular gene variant is typically found among “people who need high levels of excitement and stimulation to activate their reward system in the same capacity as those with normally functioning reward systems” (DeLisi, Beaver, Vaughn, & Wright, 2009, p. 1189).

Other Biosocial Risk Factors for Criminality There are numerous other biosocial risk factors for criminal behavior, but we have selected only a few and relate back to issues in previous chapters to show how biological factors interact with the social context to produce behavior.

In Chapter 8, we briefly discussed testosterone (T) in the context of male–female differences, but how about its effect among males only? Rowe (2002) discusses a study of the effect of T among 4,462 males. The sample was divided into high T (upper 10%) and normal T (lower 90%) and into high and low SES. The study found that antisocial behavior more than doubled (from 14.7% to 30.1%) among low-SES/high-T males compared with low-SES/normal-T males. Among high-SES males, T levels had no effect on antisocial behavior. The interaction between T and social context is further illustrated in a longitudinal study of 1,400 boys that found T levels were unrelated to conduct problems for boys with “nondeviant” or “possibly deviant” friends, but conduct problems were greatly elevated among boys with high T who associated with “definitely deviant” peers (Maughan, 2005). Thus the effects of testosterone depend quite a lot on social context, and this illustrates once again that we cannot separate biological and environmental variables and expect to understand complex behavior.

Critical Thinking Lead is a dangerous metal to the developing brain. In fact, it is a neurotoxin. People who are exposed to high levels of environmental lead may absorb the metal into their blood, which then passes the toxin into the brain, causing abnormalities in brain structure and function. This is especially true for children whose brains are developing at a rapid pace. Exposure to dangerous levels of lead has been linked to a variety of negative outcomes such as low IQ, temperamental problems, and criminal behavior. During recent years, the city of Flint, Michigan, has been mired in crisis and controversy because its water supply had been contaminated with abnormal and dangerous amounts of toxic lead. What sort of predictions would you make about the future of those children who were exposed? Should city leaders responsible for the contamination be criminally charged? What can be done to mitigate the potential harms to those exposed? Do you think that the lead-based paints found in older rundown homes could be partially responsible for the increased likelihood of criminal behavior among the poor?

In Chapter 9, we discussed a few environmental factors that influence IQ, but there are others. Exposure to noxious substances such as lead (Pb) is one such factor. For every microgram of Pb per deciliter of blood (μg/dl), there is an average decrease of one-half IQ point (Koller, Brown, Spurfeon, & Levy, 2004). An fMRI study found that brain gray matter was inversely related with average childhood Pb concentrations (the more the lead, the less the gray matter) in young inner-city adults (Cecil et al., 2008). The average childhood blood Pb concentration of this sample was 13.3 μg/dl, which is far in excess of the 2006 average of 1.5 μg/dl for the U.S. general population (Bellinger, 2008). Although

the gray matter lost to Pb exposure was relatively small (about 1.2%), it was concentrated in vital behavior-moderating areas responsible for executive functioning and mood regulation such as the PFC. Another study examining the relationship between blood Pb and verified criminal arrests found that after controlling for other relevant variables, for every 5-μg/dl increase in blood Pb, there was an increase in the probability of arrest for a violent crime of about 50% (Wright et al., 2008).

There are a number of neurological disorders that result from mothers drinking alcohol while pregnant, the most serious of which is fetal alcohol syndrome (FAS). FAS is the major preventable cause of low IQ known today (May & Gossage, 2008). Prenatal exposure to alcohol disrupts the migration and hookup of the embryo–fetus’s developing neurons in brain areas such as the frontal lobes. It also plays havoc with a number of other brain developmental processes in the womb (Goodlett, Horn, & Zhou, 2005). Because heavy drinking is most prevalent among lower-SES individuals in deprived environments (Casswell, Pledger, & Hooper, 2003), FAS rates are higher among people living there. A review of numerous studies by the National Institute of Alcohol Abuse and Alcoholism (May & Gossage, 2008) found an average rate of FAS of about 0.26 per 1,000 for the middle class and about 3.4 per 1,000 for the lowest SES class, which is about 13 times greater. The behavioral, cognitive, and personality symptoms typically found among people suffering from FAS include low IQ, hyperactivity, impulsiveness, alcoholism, poor social skills, and poor emotional and moral development, all of which are independent risk factors for antisocial behavior (Walsh & Yun, 2011).

Fetal alcohol syndrome (FAS): A chronic condition affecting the brain resulting from an individual’s prenatal alcohol exposure.

Many other substances have similar effects on neuron development and migration because whatever the mother ingests, so does her embryo– fetus. A common risk factor is maternal smoking, which puts her fetus at risk for hypoxia (intermittent reduction of oxygen available to the fetus that may lead to brain cell death) (Zechel et al., 2005) as well as the toxic chemical components of tobacco (Huizink & Mulder, 2006). Cohort studies (e.g., Brennan, Grekin, & Sarnoff, 1999) consistently find that maternal smoking during pregnancy predicts criminal behavior in the mother’s offspring independent of other factors. A review of a number of such studies found significantly increased risk for fetal tobacco- exposed individuals versus nonexposed individuals for various forms of antisocial behavior across diverse contexts and independent of other factors such as maternal SES and IQ (Wakschlag, Pickett, Cook, Benowitz, & Leventhal, 2002).

Table 10.1 summarizes the key concepts and strengths and weaknesses of biosocial perspectives and theories.

Evaluation of the Biosocial Perspective In Chapter 1, we noted Lilly and colleagues’ (2007) contention that the most dramatic developments in science come most often from new observational techniques (think of the telescope and microscope) rather than new developments in theory. The strength of biosocial approaches is that they take advantage of these new observational techniques in their ability to incorporate biological concepts and findings derived from these sophisticated physical measures into their theories. Criminologists now have access to new observational techniques in the form of DNA and neuroimaging data. Because of this, writes Matt DeLisi (2009), “Never before has the sublime interplay between nature and nurture been available for scientific discovery” (p. 266). The main stumbling block is that such studies are more difficult and far more expensive than the typical social science study. If we want genetic information, we cannot simply go to the nearest high school and survey a few hundred students. Behavior genetic studies require comparing samples consisting of pairs of identical and fraternal twins and/or adoptees, and these are difficult to come by. However, new technologies have allowed us to go straight to the DNA, thus eliminating this need, but genotyping costs about $10 per individual.

It used to be difficult to make generalizations from the typical neuroimaging study because many tended to consist of a small number of known offenders matched with a control group. However, today there are a number of ambitious studies imaging anywhere from 400 to 2,000 subjects as costs continue to come down. Paus (2010) discusses four of these studies at length, including two longitudinal studies. All studies are collecting mountains of environmental, behavioral, and cognitive data (e.g., socioeconomic status, maternal smoking, drinking, stressful life events, antisocial behavior, IQ, personality profiles). Three of the studies are also collecting DNA data. Thus biosocial studies provide

criminologists with more robust evidence than they are typically able to get, and this evidence will help them to more solidly ground their theories. Biosocial analyses of many phenomena such as medical, psychiatric, and psychological problems are now all the rage in these disciplines, and many prominent sociologists and criminologists believe this approach will prove just as useful in their disciplines. One of the most exciting advances is that some universities are offering a double major in criminology and molecular genetics or neuroscience. In any event, as new discoveries are made in genetics and neuroscience, criminology can hardly ignore them.

Policy and Prevention: Implications of Biosocial Theories It has been said that “biosocial theories may have their greatest policy applications in terms of prevention and treatment programs” (Lilly, Cullen, & Ball, 2011, p. 376). The policies suggested by the biosocial perspective are midway between the macro-level sociological suggestions aimed at whole societies and the micro-level suggestions of psychological theories aimed at already convicted criminals. Mindful of how nurturing affects both gene expression and brain development in humans, many biosocial criminologists have advocated a wide array of “nurturant” strategies such as pre- and postnatal care for all women, monitoring infants and young children through the early developmental years, paid maternal leave, nutritional programs, and a whole host of other interventions (Vila, 1997). Some of the programs, such as lead removal programs and educational programs to reduce maternal drinking and smoking, should pay generous dividends in terms of reducing IQ loss and other negative factors caused by toxic lead and maternal substance abuse. Douglas Massey (2002), former president of the American Sociological Association, called for a biosocial understanding of such things:

By understanding and modeling the interaction between social structure and allostasis [allostasis refers to the dysregulation of stress response systems such as the autonomic nervous system (ANS) discussed in the last chapter in response to chronic levels of stress], social scientists should be able to discredit explanations of racial differences in terms of pure heredity. In an era when scientific understanding is advancing rapidly through interdisciplinary efforts, social scientists in general—and sociologists in particular—must abandon the hostility to biological science and incorporate its knowledge and understanding into their work. (p. 22)

Biosocial criminologists are typically at the forefront in advocating treatment over punishment, and toward this end they have favored indeterminate over fixed sentences (Lanier & Henry, 1998). Pharmacological treatments in conjunction with psychosocial treatments have proven to be superior to psychosocial treatment alone for syndromes (e.g., alcoholism, drug addiction) associated with criminal behavior (Robinson, 2009). Of course, there are always dangers of seeking simple medical solutions to complex social problems. Requiring sex offenders to take antiandrogen treatment to reduce the sex drive raises both medical and legal/ethical issues regardless of how effective the treatment is. Prescribing selective serotonin reuptake inhibitors such as Prozac and Zoloft helps to curb low self-control and irritability, but there is always the temptation to treat everyone the same regardless of his or her serotonin levels.

One of the greatest successes of biosocial science was its pivotal role in the U.S. Supreme Court’s outlawing of the juvenile death penalty. In writing the 2005 majority opinion in Roper v. Simmons, Justice Anthony Kennedy noted the neurobiological evidence for the physical immaturity of the adolescent brain, which was brought to the Court’s attention by the American Medical Association and the American Psychological Association (Walsh & Hemmens, 2011). Thus the biosocial approach can serve to advance arguments both for prevention rather than punishment and for punishment that takes into consideration valid identifiable brain differences among people.

Robinson (2009), a sociologist who has spent much of his career researching crime prevention, states that “since biosocial criminology meaningfully integrates perspective and theories from the biological and social sciences, the approach offers much hope in the area of crime prevention. At the very least, biosocial crime prevention should be far more effective than those strategies currently utilized” (p. 243). Biosocial studies provide information about both environmental and biological risk factors and, as such, are “more likely to refine social policies by better specification of environmental factors than to divert funds from environmental crime prevention strategies” (Morley & Hall, 2003, p. 5). In other words, they will enable us to better pinpoint environmental factors that may prove fruitful in our crime prevention efforts.

Summary ❖ Behavior geneticists study the genetic underpinning of traits and characteristics in populations by calculating heritability coefficients. There are no genes “for” any kind of complex human behavior; genes simply bias trait values in one direction or another. This view is respectful of human dignity because it implies self-determinism because our genes are our genes. ❖ Gene–environment interaction tells us that the impact our environmental situation (e.g., living in a crime-ridden neighborhood) has on us depends on who we are, and gene–environment correlation tells us that who we are is a product of our unique genotype and the environments we find ourselves in. ❖ Genes have practically no influence on juvenile delinquency, probably because of the high base rate of delinquency. There are genetic effects for chronic and serious delinquents, but these few individuals tend to get “lost” in studies that combine them with those who limit their offending to adolescence. Adult criminality is much more influenced by genes. One of the reasons why we find only modest genetic effects in criminality when the traits that underlie it are strongly influenced by genes is that parents have control over their children’s behavior but little or none over the underlying traits. ❖ Evolutionary psychology focuses on why we have the traits we do and is more interested in their universality than in their variability. Crime is viewed as a normal but regrettable response to environmental conditions. By this it is meant that many human adaptations forged by natural selection in response to survival and reproductive pressures are easily co-opted to serve morally wrong purposes. ❖ In common with all sexually producing species, humans are preeminently concerned with our own survival and reproductive success.

The traits designed to assist males in their mating efforts include many that can also assist them in securing other resources illegitimately; traits designed to assist females in their parenting efforts are conducive to prosocial behavior. Mating versus parenting effort is not an either/or thing. Males and females engage in both at various times in their lives; it is just that mating effort is more typical of males and parenting effort is more typical of females. ❖ Socially cooperating species create niches that cheats can exploit to their advantage by signaling cooperation but then defaulting. Cheating is a rational strategy in the short term but invites retaliation in the long term. This is why chronic criminals rarely have successful relationships with others and why they typically die broke. ❖ Neuroscience tells us that genes have surrendered control of human behavior to the brain. Following genetic wiring to jumpstart the process, the brain literally wires itself in response to environmental input. The softwiring of our brains is an electrochemical process that depends on the frequency and intensity of early experiences. Adverse experiences can literally physically organize the brain so that we experience the world negatively, which is why nurturing, love, and attachment are so important to the healthy development of humans. ❖ Reward dominance theory informs us that the brain regulates our behavior through the behavioral inhibition system (BIS) and behavioral activating system (BAS). The BIS and BAS (underlain by serotonin and dopamine neurotransmitters, respectively) in most people are balanced, but criminals tend to have either an overactive BAS or an underactive BIS. This means their behavior is dominated by reward cues and relatively unaffected by punishment cues. ❖ Prefrontal dysfunction theory posits that the brain’s prefrontal cortex (PFC) is vital to the so-called executive functions such as planning and modulating emotions. If the PFC is damaged in any way, the individual is deficient in these executive functions and tends to be impulsive.

Exercises and Discussion Questions 1. If it could be shown with high scientific confidence that some young children inherit genes that put them at 85% risk for developing

antisocial proclivities, what do you think should be done? Should their parents be warned to be especially vigilant and to seek early treatment for their children, or would such a warning tend to stigmatize children? What are the costs and benefits of each option?

2. We know that males, especially young males, are more likely to perpetrate and be victimized by violent crimes. Provide a plausible evolutionary explanation for this.

3. How might reward dominance theory add strength and coherence to low self-control theory? 4. Explain why the traits underlying mating versus parenting effort are related to crime. 5. Discuss why understanding the biological and environmental risk factors for criminal behavior is superior to understanding only one or

the other in isolation.

Useful Websites Anatomy of the brain. www.neuroguide.com/index.html

Evolutionary psychology. http://epjournal.net/blog

Institute for Behavioral Genetics. http://www.colorado.edu/ibg

The human brain. www.fi.edu/brain/index.htm

Chapter Terms Allele 187

Adaptive behavior 192

Behavior genetics 184

Behavioral activating system 191

Behavioral inhibition system 191

Evolutionary psychology 192

Fetal alcohol syndrome (FAS) 198

Flight/fight system 191

Gene/environment correlation 185

Gene/environment interaction 185

Genes 184

Genetic polymorphisms 187

Genotype 184

Heritability 184

Mating effort 195

Neurons 189

Neurotransmitters 189

Nonshared environment 184

Parenting effort 195

Phenotype 184

Prefrontal cortex 191

Reinforcement sensitivity theory 191

Reward dominance theory 191

Shared environment 184

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