nature and nurture

• The nature-nurture debate

  Concerned with the extent to which aspects of behaviour are a product of inherited or acquired characteristics
• Heredity

  The genetic transmission of both mental and physical characteristics from one generation to another
• Environment

  Any influence on human behaviour that is non-genetic. This may range from prenatal influences in the womb through to cultural and historical influences at a societal level. It includes biological influences, e.g. the food you eat may affect your mental development and physical growth
• Interactionist approach

  A way to explain the development of behaviour in terms of a range of factors, including both biological and psychological ones. Most importantly such factors don't simply add together but combine in a way that can't be predicted by each one separately i.e. they interact
• Diathesis-stress model

  • suggests behaviour is caused by a biological or environmental vulnerability (diathesis) which is only expressed when coupled with a biological or environmental 'trigger' (stressor)
  • e.g. a person who inherits a genetic vulnerability for OCD may not develop the disorder but, if combined with a psychological trigger (e.g. a traumatic experience) this may result in the disorder appearing
• What is epigenetics?

  A change in genetic activity without altering the genes themselves, influenced by environmental factors.
• What causes epigenetic changes?

  Interaction with the environment, such as smoking, diet, trauma, and life experiences.
• How do environmental factors affect our genes in epigenetics?

  They leave chemical 'marks' on DNA, which can switch genes on or off and alter how they are expressed
• Why can lifestyle choices like smoking have long-term effects, even after quitting?

  Because they cause epigenetic changes that permanently affect gene expression.
• Can epigenetic changes affect future generations?

  Yes. Epigenetic changes can be passed down, influencing the genetic expression of children and even grandchildren.
• How does epigenetics impact the nature-nurture debate?

  It introduces a third element: the life experiences of previous generations can influence gene expression in descendants.
• What does "nature" refer to in psychology?

  Inherited influences or heredity; psychological traits like intelligence and personality are determined by biological factors (genes).
• Which philosopher supported the nature view and what did he believe?

  Descartes; he argued that human characteristics and some knowledge are innate.
• What does "nurture" refer to in psychology?

  The influence of experience and the environment on behaviour and development.
• Which philosopher supported the nurture view and what was his idea?

  Locke; he believed the mind is a 'tabula rasa' (blank slate) shaped by environmental experiences.
• What are some examples of environmental influences according to Lerner?

  Prenatal influences (e.g. smoking, music) and postnatal factors (e.g. social conditions)
• How is the influence of nature and nurture measured in psychology?

  Using concordance rates (correlation coefficients) to estimate heritability of traits.
• What is heritability?

  The proportion of differences between individuals, with regards to a particular trait, that is due to genetic variation
• What is the heritability estimate for intelligence (IQ) according to Plomin (1994)?

  Around 0.5 – suggesting that intelligence is roughly 50% genetic and 50% environmental
• nature side of the debate is founded in nativist theory that knowledge/abilities are innate
• nurture side of the debate is founded in empiricist theory that knowledge derives from learning and experience