2. Risk Factors
• Origins of criminal behavior are complex
• Result from a combination of risk factors
– Biological and environmental factors
• Risk factors interact and aggravate one
another
• The more risk factors present = higher
likelihood of criminal behavior
4. Biological Level of Analysis
• Various biological factors can contribute to
criminality
• Factors such as:
– Genetics
– Brain abnormalities
– Nuerochemical imbalances
5. Genetics
• Christiansen (1977) studied 3586 sets of
Danish twins
• Found that there may be some genetic factors
in criminal behavior…but concordance rates
are very low
• Other factors may play a more important role
6. Limitation of Twin Studies
• Monozygotic twins are often treated more
similarly than dizygotic twins are
7. Hutchins and Mednick Adoption Study
• 32.6% of sons had a criminal record w/ both a
a biological and adoptive father with criminal
records
• 21.4% if only his biological father had a
criminal record
• 11.5% if only adopted father had record
• Shows importance of environmental factors in
combination with genetic factors in
determining behavior
8. Limitations of Adoption Studies
• Children are often placed in an environment
that is similar to their original environment
• Some children adopted years after birth
– No control of length of time with birth-family
9. Limitations of Genetic Arguments for
Criminal Behavior
• The term “criminal behavior” itself
– Crimes can range from murder to jaywalking to
tax evasion
• A gene for “crime” probably doesn’t exist
• Genetic theorists have a difficult time
explaining why criminal behavior tends to
change over a lifespan
– Peak criminal behavior at age 20
– Decline after 30
10. The Brain
• Looks at interrelationship between emotions
and decision making
• Emotions are controlled by the brain’s limbic
system
• Decision making takes place in frontal lobe
11. Blair et al. (1999)
• Impairment of pathways between the
amygdala and frontol lobe in the brain
• Makes it difficult to moderate emotional
reactions
– Effects how the individual interacts with others
• Never appropriately develops empathy or
guilt
• Acts more impulsively
12. Frontal Brain Hypothesis
• Theory that a malfunctioning relationship
between the frontal cortex and limbic system
may cause criminal behavior
• Brain damage may cause behavioral problems
– Antisocial behavior
• Hypothesis does not explain all criminal
behavior
13. Neurotransmitters and Hormones
• Explains the significant gender difference in crime
• In 2004:
– 90.1% of murderers were male
– 82.1% of violent criminals were male
• Low levels of serotonin have been linked to
antisocial and impulsive behavior
– Men generally have lower levels
• Often higher testosterone levels = more
aggressive criminals
14. Biological Factors
• These factors alone are not enough to cause
violence
– With the exception of severe brain damage
• These factors must be combined with
cognitive and social factors as well
16. Yochelson and Samenow (1976)
• Criminal thinking has cognitive distortions
(errors in thinking)
– Blaming others for their own failures
– Super-optimism (extremely unrealistic)
– Unable to accept mistakes when proven wrong
– Reducing/limiting significance of a behavior
– Exaggerating accomplishments and abilities
17. Cornish and Clark (1987)
• Rational Choice Theory: Criminal behavior is
the outcome of a reasoned decision-making
process
• Assumes that criminals seek to benefit from
the crimes they commit
• If benefits > costs, they carry out the crime
18. Bennett and Wright (1984)
• 3 factors affecting decision to commit crime:
– Risk (chance of getting caught)
– Financial reward
– Ease of entry
• Supports the theory that a clear decision-
making process underlies criminal activity
• Limitation: can’t ask successful burglars—only
the ones who are caught!
20. Sociocultural Level of Analysis
• Considers how society and culture affects our
behavior
• Factors:
– Social and cultural expectations
– Economic and political realties that exist where
we live
21. Poverty
• Messner (1988): instead of focusing on
differences in income, we need to look at
structural poverty
– Single-parent families, low levels of education,
high infant mortality rates, low social mobility
• Income levels alone does indicate crime
22. Unemployment
• Correlation between rates of unemployment
and rates of crime
– Unemployment can damage self-esteem
– Feels that life is meaningless
– Change in status
– Boredom/free time!
23. Social factors + Biological factors
• Poverty brings higher stress on the mother of
a developing child
– Affects the fetus
– Can impair brain function
24. Labels
• Self-fulfilling prophecy: When we are given a
label we often live up to that expectation
• Jahoda (1954): Ashanti people feel day of the
week a child is born on predicts temperament
• Wednesdays are supposed to be aggressive
and problematic; Mondays are calm and
peaceful
– High number of arrests for boys born Wednesday
– Low number for Monday
25. Three Levels Combined
• Biological factors may affect an individual’s
thought process
• Thought processes may affect his/her social
development
• Socio-economic status could have an effect on
the health of an expectant mother, and thus
the development of the child