Description of biological factors that relates to crime

1. Chapter 4
Biology and Crime

2. Causes of Crime
 Why does a person commit a crime?
 What causes crime and deviance?
 Are people basically good?
 Why are some people violent and
aggressive?
 Are people motivated only by self-interest?
 Criminologists search for answers to
those types of questions.

3. Criminology
 Criminology seeks to find the cause of
crime and deviant behavior.
• Crime
 violation of the criminal law for which there is
no legal justification.
• Deviance
 violation of social norms that specify
– appropriate or proper behavior under a particular set
of circumstances (often includes crime).

4. 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.

5. 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.

6. 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

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

8. Phrenology

9. Franz Joseph Gall (1758-1828):
Phrenology
 Phrenology, study of the
shape of the head and its
relationship to human
behavior, focused on the
head and brain in what Gall
called “cranioscopy.”
 The brain is the organ of the
mind.
 The brain consists of
localized faculties or
functions.

10. Franz Joseph Gall (1758-1828):
Phrenology
 The shape of the skull reveals
underlying development (or lack of
development) of areas within the brain.
 A personality can be revealed by a
study of the skull.

11. The basic assumptions of
Gall…
 That moral and intellectual faculties are innate.
 That their exercise or manifestation depends on
organization.
 That the brain is the organ contains all of the capacities
for sentiments and faculties.
 That the brain is composed of many particular organs
that fulfill different intellectual and emotional capacities.
 That the form of the head or cranium represents the form
of the brain, and thus reflects the relative development of
the brain organs.

12. The basic assumptions of
Gall…
 That moral and intellectual faculties are innate.
 That their exercise or manifestation depends on
organization.
 That the brain is the organ contains all of the capacities
for sentiments and faculties.
 That the brain is composed of many particular organs
that fulfill different intellectual and emotional capacities.
 That the form of the head or cranium represents the form
of the brain, and thus reflects the relative development of
the brain organs.

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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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.

21. 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)

22. 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

23. 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?

24. 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.

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

26. 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

27. 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.

28. 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)

29. 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.

30. Cross Fostering Analysis
Mednick et al. (1984)
Biological Parents
Criminal?
Adoptive
Parents
Criminal? YES NO
YES 24.5% 14.7%
NO 20.0% 13.5%

31. 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

32. 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

33. 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

34. 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.

35. 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

36. 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.

37. 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

38. 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

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

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

41. 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

42. 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.

43. 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.

44. 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

45. 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

46. 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.

47. 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

48. 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

49. 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

50. 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