The Nature-Nurture Debate

• What does nature refer to in psychology?

  Inherited influences
• Who argued that all human characteristics are innate?

  Descartes
• What does nurture refer to in psychology?

  Influence of experience and the environment
• What did Locke argue about the mind at birth?

  The mind is a blank slate
• What did Lerner identify regarding the environment?

  Different levels of the environment
• What are prenatal factors in the context of Lerner's work?

  Physical and psychological influences before birth
• What does concordance measure in psychology?

  The similarity of traits between two people
• How does concordance relate to inheritance?

  It estimates the extent of trait inheritance
• What is heritability in psychology?

  Proportion of differences due to genetic variation
• What is the nature-nurture debate about?

  Influence of nature versus nurture on behavior
• Why is the nature-nurture debate not truly a debate?

  Characteristics arise from both influences
• What approach do psychologists typically take regarding nature and nurture?

  Interactionist approach
• What does the diathesis-stress model suggest?

  Behavior is caused by biological vulnerability and stress
• What is epigenetics?

  Study of heritable traits without DNA changes
• How do epigenetic changes occur?

  Through interaction with the environment
• What can epigenetic changes influence?

  Gene expression and future generations
• What historical event did Susser & Shang Lin (1992) study?

  The Dutch famine during World War II
• What was a significant finding from Susser & Shang Lin's research?

  Low birth weight babies had higher schizophrenia risk
• How does understanding heritability inform genetic counseling?

  It helps assess the likelihood of developing disorders
• What do adoption studies help to separate?

  Influences of nature and nurture
• What did Rhee & Waldman (2002) find about aggression?

  Genetic influences accounted for 41% of variance
• What is niche-picking in the context of nature and nurture?

  Choosing environments that match one's nature
• What did Plomin (1994) suggest about children's environments?

  Children create their own nurture based on nature
• What are the key concepts in the nature-nurture debate?

  • Nature: genetic influences
  • Nurture: environmental and experiential influences
  • Interactionist approach: both influences are important
  • Diathesis-stress model: biological vulnerability + environmental stress
  • Epigenetics: heritable traits without DNA changes
• What are the implications of epigenetics in psychology?

  • Life experiences can affect future generations
  • Historical events can leave epigenetic markers
  • Understanding heritability aids in genetic counseling
  • Adoption studies help separate nature and nurture influences
• What is a strength for Nature in the Nature-Nurture debate?

  Epigenetics

  • In 1944, the Nazis blocked the distribution of food to the Dutch people, resulting in 22,000 people dying of starvation
  • Susser & Shang Lin (1992) report that women who became pregnant during the famine went on to have low birth weight babies, and these babies were twice as likely to develop schizophrenia when they grew up compared to other populations
  • This supports the view that the life experiences of previous generations can leave epigenetic markers that influence the health of their offspring
• What is a strength for the Nature-Nurture debate?

  Real World Application

  • Research suggests that OCD is highly heritable, and such understanding can inform genetic counselling because high heritability does not mean it is inevitable that the individual will develop the disorder
  • This means people with a high genetic risk of OCD can receive advice about the likelihood of developing the disorder and how to prevent it
  • This shows that the debate is not just a theoretical one but it is important at a practical level to understand the interaction between nature and nurture
• What is a strength for the Nature-Nurture debate?

  Adoption Studies

  • Adoption studies are useful because they separate the competing influences of nature and nurture; if adopted children are found to be more similar to their adoptive parents, this suggests the environment is the bigger influence, whereas, if adopted children are more similar to their biological parents, then genetic factors are presumed to dominate
  • Rhee & Waldman (2002) found that genetic influences accounted for 41% of the variance in aggression
  • This shows how research can separate the influences of nature and nurture
• What is a limitation for the Nature-Nurture debate?

  Niche-picking

  • However, research suggests that this approach may be misguided, as it is difficult to separate the two
  • Plomin (1994) found that people create their own ‘nurture’ by actively selecting environments that are appropriate to their ‘nature’, for example a naturally aggressive child will feel more comfortable with other children who display similar behaviour
  • This suggests that it does not make sense to look at evidence of either nature or nurture