Heredity

Heredity


Heredity: the transmission of characteristics from parents to offspring

  • Physical traits: height, hair color, eye color

  • Psychological traits: shyness, leadership, aggressiveness

  • Disorders: depression, schizophrenia, bipolar

Nature vs Nurture

  • Nature refers to what people inherit (GENETICS)

    • Nature Advocates: believe that people’s traits and personalities are primarily determined by biological makeup

  • Nurture refers to environmental factors (ENVIRONMENT)

    • Nurture advocates: argue that the environment we live in and our everyday experiences NOT our biological inheritance determine how we behave and think

  • Both views are considered extreme; in reality, it’s both combined

  • Biology influences us to act in certain ways, but our environment can modify these plans

  • HEREDITY IS NOT OUR DESTINY

How do we study N v N?

  • Kinship Studies: degree to which someone is related

    • Identical twins = 100%

    • Fraternal twins = ~50%

  • Use this info to determine how much of a trait is influenced by genetics and how much by environment

  • Two kinds of Kinship Studies:

    • Twin studies: study characteristics of identical twins. Differences between identical twins must be the result of environmental factors because identical twins are 100% the same genetically

    • Adoptee studies: to eliminate the fact that most identical twins have the same environment, adoptee studies will focus on identical twins who have been separated at birth and raised by different families

    • Minnesota Study of Twins Reared Apart

      • Major adoptee study starting in 1979 

      • Concluded personality traits are about 50% nature and 50% nurture

      • Psychological and personality traits MOST influenced by heredity (intelligence, traditionalism, risk avoidance, aggression, leadership, mannerisms)