biology and crime early theories of biology and crime modern approaches – behavioral genetics –...

Biology and Crime

• Early Theories of Biology and Crime

• Modern Approaches– Behavioral Genetics– Biological Factors Related

to Crime– Biosocial Theory – Policy Implications

Early Biological Theories (1 of 2)

▪ Early history of criminology • Many early criminologists were physicians• General idea = the presence of certain physical traits

makes criminal behavior more likely

Early Biological Theories (2 of 2)

1. Phrenology2. Lombroso’s “born criminal”3. Physical deficiencies4. 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 evolutionary “throwbacks”▪ Physical traits (Stigmata)• Peaked nose (as bird of prey)• Sloped forehead, large jaws• Strong canine teeth (as with carnivores)• General hairiness of the body• Low foreheads

Lombroso’s “Born Criminal” (3 of 3)

▪ Types of criminals ▪ Insane

▪ Idiots, drug addicts, moral degenerates

▪ Criminaloids▪ Those who have less pronounced physical stigmata

▪ 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

▪ Focused on single, direct cause of crime that cannot be changed

▪ Policy implication = Eugenics• Remove these individuals from society through

forced sterilization, internment in camps, or death• Eugenics movement waned after WWII

The demise of early positivism

1. Poor theory – Single biological trait as direct cause of crime.

2. Poor/biased research– Any small criminal/non-criminal difference were

assumed to reflect the superiority of non-criminals

3. Dangerous policy implications– Eugenics movement

Largely discredited by Sociologists by 1950.

Modern Biological Approach (2 of 2)

1. Behavioral genetics 2. Biological correlates of criminal behavior3. Biosocial theory4. Evolutionary theory (sociobiology)

Behavioral Genetics (1 of 5)

Can criminality be inherited?Trying to separate nature (genes) from nurture

(environment)▪ 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 (poor parenting,

shared environment) could easily explain this finding.

Behavioral Genetics (3 of 5)

Twin studies▪ Compare monozygotic (MZ) and dizygotic (DZ) twins▪ MZ twins have higher concordance rates than DZ

twins: Danish Study (Christiansen, 1979)• MZ=52%• DZ=22%

▪ 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.

Cross Fostering AnalysisMednick et al. (1984)

Biological Parents Criminal?

Adoptive Parents Criminal? YES NO YES 24.5% 14.7% NO 20.0% 13.5%

“Genetic” Effect“Genetic” Effect

Environment

Environment

Behavioral Genetics (5 of 5)

Molecular genetics ▪ Isolates particular genes

that may relate to crime– DNA– Bases (A,T,C,G)– Gene

Gene-linkage– Hans Brunner Case as

“OGOD”

Human Genome Project

Many biological factors may contribute to criminal behavior

1. Neurological factors2. Autonomic nervous system3. Biological harms4. Hormones

Neurological Factors (1 of 2)

▪ 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 2)

▪ Neurochemical measures▪ Neurotransmitters (like serotonin) allow cells to

communicate with each other. ▪ Low levels of serotonin are sometimes linked

with impulsive and aggressive behavior• Monoamine oxidase A (MAOA) gene implicated in

several studies – Hans Brunner study– Interaction between specific forms of the gene and

violence/crime (New Zealand study)

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 2)

▪ 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

Biosocial Theory

▪ Combinations of environmental and biological risk cause criminal behavior

1. Life-course-persistent offending2. Personality-based theory3. 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

▪ Argue that LCP path is caused by neurological deficits and ineffective parenting

Personality-Based Theory

▪ 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.

▪ Caspi et al. = 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. Good example of a biology x environment interaction.

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 appear to be related to criminal behavior:▪ Inherited▪ Results of biological harm

▪ Biological factors contribute to criminality in certain environmental circumstances.

▪ “Biosocial” Theories

Biological Theories Criticisms

▪ 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)

▪ Still fear of 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)

▪ The upside? Criminality as a public health problem▪ Prenatal care for at-risk mothers▪ Strengthen environmental counterbalances for

children with biological risk indicators