adoption studies

• What do adoption studies investigate regarding behavior?

  Nature versus nurture influences
• How do adopted children differ from their biological parents?

  They share genes but not upbringing
• What should happen if a characteristic is genetic in adoption studies?

  It should appear in biological children
• What was the focus of Heston's 1966 study?

  Schizophrenia in adopted children
• What type of study did Heston conduct?

  Longitudinal adoption study
• How many participants were monitored in Heston's study?

  94 participants
• What was the criterion for the first group of participants in Heston's study?

  Biological mothers had schizophrenia
• What was the criterion for the second group of participants in Heston's study?

  Biological mothers were mentally healthy
• What was the risk of developing schizophrenia if one parent had it?

  10%
• What was the prevalence of schizophrenia in the general population?

  About 1%
• What did Heston's findings suggest about schizophrenia?

  There is a genetic component
• What percentage of children with schizophrenic mothers developed schizophrenia in Heston's study?

  10%
• What percentage of children with non-schizophrenic mothers developed schizophrenia?

  0%
• What are the strengths of adoption studies?

  • Assess nature vs. nurture
  • Produce quantitative data
  • Easy to analyze
• What are the weaknesses of adoption studies?

  • Sample bias from volunteer families
  • Similarity in socioeconomic status
  • Early upbringing as a confounding variable