Chapter 4 Biology and Crime Lee Ayers-Schlosser, Southern Oregon University

Chapter Objectives (1 of 2) Learn the history of biological explanations of criminal behavior. This includes early biological theories and their policy implications, including eugenics. Understand the methodologies used by scientists in their attempt to separate nature (genetics) from nurture (environment). This includes twin studies, adoption studies, and molecular genetics.

Chapter Objectives (2 of 2) Grasp the known biological correlates of crime, which range from neurotransmitters to biological harms such as lead poisoning. Understand biosocial theories of criminal behavior and how policy implications differ between modern biosocial explanations and early biological theories. Understand the basis of evolutionary theories of criminal behavior and to link this with a specific evolutionary theory.

You Are the Criminologist Can Biological Risk Markers Identify Potential Criminals? Futuristic fiction: An instrument can be used to screen for a particular biological trait as a predictor of violent behavior. Do you think that there is a genetic component to criminal behavior? What kinds of ethical dilemmas would such an instrument create?

Early Biological Theories (1 of 2) Early history of criminology (many early criminologists were physicians) Theory: the presence of certain physical traits makes criminal behavior more likely

Early Biological Theories (2 of 2) 1. Phrenology 2. Lombroso’s “born criminal” 3. Physical deficiencies 4. The XYY “supermale” 5. Somatotype theory

Phrenology Exterior of the skull reflects the mind Bumps on the head indicate criminal tendencies

Lombroso’s “Born Criminal” (1 of 3) Cesare Lombroso 19th‑century Italian physician Led the movement from classical school to scientific positivism Major contributions Study of the individual offender and crime conditions Application of statistical methods to data collection and analysis, as well as multiple‑factor analysis Use of typological methods to classify and study criminals and examine criminological phenomena

Lombroso’s “Born Criminal” (2 of 3) Atavism Criminals as amoral, not fully evolved Physical traits Low foreheads Broad noses Small cranial capacities

Lombroso’s “Born Criminal” (3 of 3) Types of criminals Insane Idiots, drug addicts, moral degenerates Criminaloids Those who have physical stigmatas and whose moral degeneracy is less pronounced Criminals by passion Passion (like love, hate, honor) fueled their criminal rage

Physical Deficiencies Charles Goring Criminal behavior related to defective intelligence Earnest Hooten Criminals physiologically inferior Physical traits Low foreheads Pinched noses Compressed faces Narrow jaws

Somatotype Theory (1 of 3) Developed by William Sheldon (supported by the Gluecks at Harvard) Body build (somatotype) linked to: Behavioral tendencies Temperament Life expectancy Susceptibility to disease

Somatotype Theory (2 of 3) Basic body types Endomorph Fat, soft, and round Tend to be extroverts Ectomorph Thin and wiry Easily worried, sensitive, and introverted Mesomorph (most criminals) Muscular Gregarious, aggressive, assertive, and action oriented

Somatotype Theory (3 of 3) Explanations Those with muscular builds tend to enjoy the physical activity involved in crime. Mesomorphic body type may have an advantage in the rough‑and‑tumble activities of street crime. Mesomorph is perceived as a threat and is therefore more likely to be arrested and/or incarcerated.

The XYY “Supermale” Chromosomal abnormality (extra Y chromosome) May be more likely to engage in criminal behavior (but not violent behavior) Extremely rare chromosome structure (less than 0.1% of total male population)

Policy Implications of Early Biological Research Focuses on single factors that cannot be changed Policy solution: remove these individuals from society Eugenics—forced sterilization

Modern Biological Approach (1 of 2) Despite the tarnished legacy, there has been a comeback in biological research in recent years.

Modern Biological Approach (2 of 2) 1. Behavioral genetics 2. Biological correlates of criminal behavior 3. Biosocial theory 4. Evolutionary theory (sociobiology)

Behavioral Genetics (1 of 5) Can criminality be inherited? Family studies Twin studies Adoption studies Molecular genetics

Behavioral Genetics (2 of 5) Family studies Early studies traced family history (Jukes) Modern studies look at parent’s crime (Sampson and Laub) Findings: Parental crime consistently predicts children’s criminal behavior. Criticism: Environment could easily explain this finding.

Behavioral Genetics (3 of 5) Twin studies Compare monozygotic (MZ) and dizygotic (DZ) twins Findings: MZ twins have higher concordance rates than DZ twins. Criticism: People may treat MZ twins more similarly MZ twins more likely to share friends (including delinquent peers)

Behavioral Genetics (4 of 5) Adoption studies Compare criminal record of adopted children with their biological and adoptive parents. Findings: Children’s criminal behavior relates more to biological parents. Criticism: Adoption agencies might have biased placements.

Behavioral Genetics (5 of 5) Molecular genetics Isolates particular genes that may be related to criminal disposition Helped by Human Genome Project Findings: Some potential genes have been identified (e.g., predisposition for antisocial behavior). Criticism: Any particular gene will have only minimal effect on human behavior.

Biological Correlates (1 of 2) Physiological differences exist between criminals and noncriminals. A wide range of factors potentially contribute to criminal behavior.

Biological Correlates (2 of 2) 1. Neurological factors 2. Autonomic nervous system 3. Biological harms 4. Hormones

Neurological Factors (1 of 3) Direct measures of the brain Prefrontal cortex Executive functions (e.g., cognition, attention, impulsivity) MRI and PET scans analyze brain structure and activity Differences in the frontal lobe exist between criminals and noncriminal control groups

Neurological Factors (2 of 3) Neurochemical measures Neurotransmitters (like serotonin) allow cells to communicate with each other. Low levels of serotonin are linked with impulsive and aggressive behavior.

Neurological Factors (3 of 3) Indirect measures Use IQ and other neuropsychological tests to predict delinquency Test executive functions (which reflect differences in brain functioning) Potentially reflect underlying neurological deficits

Autonomic Nervous System Controls how the body reacts to stimuli (heart rate, gland secretions) Some criminals have lower resting heart rates than noncriminals. Studies of skin conductance (sweat) yield mixed results. Criminals potentially have low levels of arousal.

Biological Harms (1 of 3) Perinatal risks linked with criminality Smoking (cigarettes, marijuana) Alcohol consumption (fetal alcohol syndrome) Delivery complications Low birth-weight children More pronounced effect in unstable families

Biological Harms (2 of 3) Environmental toxins Lead exposure Highly toxic substance (especially for young children) Found in lead paint and leaded gasoline Can cause serious health and behavioral problems Linked to delinquent behavior

Biological Harms (3 of 3) Nutrition and diet Focus on high levels of sugar and junk food intake Relates to antisocial behavior, irritability Some studies showed that hypoglycemia is linked with violent, impulsive behavior Not well supported by research

Hormones Testosterone (male androgen) Premenstrual syndrome (PMS) Higher levels linked to antisocial, aggressive behavior Premenstrual syndrome (PMS) Relationship to female offending unsupported by research

Biosocial Theory Combinations of environmental and biological risk cause criminal behavior 1. Life-course-persistent offending 2. Personality-based theory 3. Female delinquency

Life-Course-Persistent Offending Developed by Terrie Moffitt Adolescent-limited (AL) offenders Criminal behavior limited to adolescence Life-course-persistent (LCP) offenders Chronic offending starts early in life Caused by neurological deficits and ineffective parenting

Personality-Based Theory Developed by Hans Eysenck Personality traits driven by underlying biology cause crime. Children with low arousal will be difficult to socialize. In criminal families, low arousal might prevent children from learning criminal behavior.

Female Delinquency Early onset of puberty is linked to criminal behavior. This is true for girls in coed schools, but not for those in all-girls schools. Conclusion: Girls who start puberty early attract the attention of older, crime-prone males, which may lead to delinquency.

Evolutionary Theory (1 of 2) Uses principles of evolution to explain modern human behavior Research Rape “Cads and dads” theory Criticism Difficult if not impossible to test Evidence sometimes runs counter to predictions

Evolutionary Theory (2 of 2) Rape Evolutionary processes allow males who are pushy and aggressive in the pursuit of sex to pass on their genes successfully. “Cads and dads” theory Alternative strategies for reproductive success Cads—pretend caregivers who really want to reproduce with as many females as possible Dads—invest time and energy to help nurture and raise offspring

Summary Many biological factors involved in criminal behavior: Inherited Results of biological harm Biological factors contribute to criminality in certain environmental circumstances. Humans may be partially driven toward crime by natural forces beyond their control.

Biological Theories Criticisms (1 of 2) Lombrosian fallacy Incarcerated persons not representative of criminals in general population Bias from social structure and criminal justice system

Biological Theories Criticisms (2 of 2) Ignores some types of crimes White-collar Organized Political crime Focuses on aggression or antisocial behavior in children and street crime in adults

Policy Implications (1 of 2) Fears ethical problems Biology not necessarily destiny Provide unsound justifications for the control of minority populations New eugenics Gene therapy Discrimination based on presence of biological risk indicators

Policy Implications (2 of 2) Criminality as a public health problem Prenatal care for at-risk mothers Strengthen environmental counterbalances for children with biological risk indicators

Conclusion Lessons from the biological school are limited to certain crimes and offenders. More research is needed. Nature vs. nurture relationship Interdisciplinary study with criminologists and physical and medical scientists