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Chapter 4
Biology and Crime
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.
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 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
Modern Biological Approach (1 of 2)
▪ Despite the tarnished legacy, there has
been a comeback in biological research in
recent years.
 Is the new stuff any better?
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 behavior
3. Biosocial theory
4. 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 Analysis
Mednick et al. (1984)
Adoptive
Parents
Criminal?
YES
NO
Biological Parents
Criminal?
YES
NO
24.5%
14.7%
20.0%
13.5%
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
Human Genome
Project
Biological Correlates
▪ Physiological differences exist between
criminals and noncriminals.
▪ A wide range of factors potentially
contribute to criminal behavior.
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 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
Hormones
▪
Testosterone (male androgen)
▪
▪
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
▪
▪
Life-course-persistent (LCP) offenders
▪
▪
Criminal behavior limited to adolescence
Chronic offending starts early in life
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.
▪ Humans may be partially driven toward
crime by natural forces beyond their
control.
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
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