Explanations of Criminal Behavior

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Explanations of Criminal Behavior

• Theories of Criminal Behavior

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Who commits crime?

• Brainstorm reasons for criminal behavior based on
  these three catagories
• Social
• Economic
• Biological
• Other???

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Theories of Criminal Behavior

• Biological Theories genetic and physiological.
  Cause is the individual, no real part played by
  social factors.
• Personality Theories certain types inclined to
  crime
• Social Learning learned criminal ways
• Issue Nature vs. Nurture debate

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Old school theories
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Cesare Lombroso

• Lombroso in 1876 argued that the criminal is a
  separate species, a species that is between
  modern and primitive humans. He argued that the
  physical shape of the head and face determined
  the "born criminal".

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• William Sheldon believed that body types
  determined criminality.
• endomorphic (fat and soft) sociable and relaxed.
• ectomorphic (thin and fragile) are introverted
  and restrained
• Mesomorphic CRIMINAL (muscular and aggressive)
  tend to be aggressive and adventurous.
• Sheldon found that many convicts were
  mesomorphic, and they were least likely to be
  ectomorphic (Sheldon et al 1949).

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MODERN THEORIES
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Neurophysiological

• Raine 1994 used PET scans to study the living
  brains of impulsive killers. Damage was found in
  the pre-frontal cortex, which controls impulsive
  behavior.

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Neurophysiological
PET Scanner
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Neurophysiological
PET Scan
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Neurochemical

• The brains chemistry can be influenced by
  diet, for example, food additives, pollution or
  hypoglycaemia (low blood sugar levels associated
  with forms of diabetes).
• The TWINKIE DEFENSE A murderer in California
  claimed that the sugar in Twinkies caused him to
  become homicidal.

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Neurochemical

• STEROIDS? Individuals who take large amounts
  of steroids can become extremely violent (known
  as "roid rage"). Steroids, usually taken to
  increase muscle growth, also increase
  testosterone levels. However a direct link
  between steroids and violence has not been made.
• http//www.youtube.com/watch?vhN7rf4Mm1QA

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Family Studies
Nature vs. Nurture debate
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Twin studies Genetic influence on crime

• IDENTICAL TWINS (same genes and gender) that have
  been separated at birth and brought up separately
  have been studied
• The degree of similarity between two twins is
  known as the concordance rate.
• This rate was compared with FRATERNAL twins who
  are brought up separately
• Looking at a number of studies the average
  concordance rate is 55 for IDENTICAL twins and
  17 for FRATERNAL twins (Bartol, 1999).

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Psychopathy or Sociopathy? Psycho or
Weirdo?

• PSYCHOPATHS (NATURE)
• Psychologists use the term psychopathy to
  describe a psychological disorder that is the
  product of a combination of
• psychological,
• biological,
• genetic and,
• to a lesser degree environmental factors.
• Studies have shown that psychopaths have inherent
  temperamental differences such as
• impulsivity,
• fearlessness, and
• reduced physiological responsiveness
• resulting in a high level of risk-seeking
  behavior and lack of adherence to social norms.
• Recent research has demonstrated that early signs
  predictive of psychopathy can be present at a
  very young age (Viding 2005, Glenn 2007).

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Sociopathy

• Sociopaths (Nurture)
• Sociologists typically prefer the term sociopath.
• sociopaths possess
• reasonably normal temperaments their social
  pathology more a result of negative sociological
  factors such as parental neglect, running with
  the wrong crowd, poverty, and extremely low or
  extremely high intelligence(Lykken 1995).
• Although all personality disorders are likely to
  be the result of some level of interaction
  between genetic predispositions and environmental
  factors, according to these definitions,
  psychopathy is defined primarily by hereditary
  and sociopathy by environmental influences.

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Adoption studies

• A study looked at court convictions in a
  small European country and found 14,000 adoptees
  amongst them.
• The criminal records of their biological and
  adoptive parents were then investigated. Many of
  the adoptees had criminal biological parents
  (particularly strong relationship for sons and
  fathers).
• There was no relationship in the types of crime
  committed.
• HOWEVER Where there was an improvement in
  social conditions by adoptive parents there was a
  reduction in crime (going against the genetic
  explanation).