genetic factors in aggression

• What percentage of variance in direct aggressive behavior is attributed to genetic factors according to Coccaro et al (1997)?

  50 percent
• What did the twin studies by Coccaro et al (1997) focus on?

  Direct aggressive behavior in adults
• How many adoptions were studied by Hutchings and Mednick (1975)?

  Over 14,000
• What was a significant finding from Hutchings and Mednick's study on adopted boys?

  Many had biological parents with convictions
• What did the meta-analysis by Miles and Carey (1997) conclude about aggression?

  Strong genetic influence exists in aggression
• How did the influence of rearing environment change with age according to Miles and Carey (1997)?

  Decreased with age, while genes increased
• What did Rhee and Waldman (2002) conclude about aggressive anti-social behavior?

  It is largely a product of genetic contributions
• What are some problems associated with sampling in genetic studies of aggression?

  Sampling may not represent the general population
• What difficulties arise in determining the role of genetic factors in aggression?

  Complex interactions with environmental factors
• What gene is associated with aggressive behavior?

  MAOA gene
• How does the MAOA gene influence aggression?

  It regulates serotonin metabolism in the brain
• What is associated with low levels of serotonin?

  Impulsive aggressive behavior
• What variant of the MAOA gene did Caspi et al (2002) discover?

  MAOA-L variant
• What was the outcome for individuals with the MAOA-L variant who were maltreated?

  More likely to exhibit anti-social behavior
• How did maltreatment affect children with the MAOA-L variant?

  It increased the likelihood of anti-social behavior
• What was the behavior of children with the MAOA-L variant who were not maltreated?

  Did not display anti-social behavior
• What is the role of environmental factors in aggression?

  They interact with genetic predispositions
• What are the implications of genetic studies on understanding aggression?

  They highlight the complexity of aggression's origins
• How do MAOA gene variants relate to behavior?

  They influence the likelihood of aggression
• What is the significance of twin and adoption studies in aggression research?

  They help isolate genetic influences on behavior
• How does childhood maltreatment affect genetic predispositions?

  It can trigger the expression of anti-social behavior