Nature-nurture debate Flashcards
What is the nature-nurture debate?
Concerned with the extent to which aspects of behaviour are a product of inherited or acquired characteristics
What is the interactionist approach?
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- Any behaviour/characteristic arises from a combination of nature and nurture (e.g: eye colour is .80 heritable- Bräuer and Chorpra)
- E.g: Attachment type- Bowlby: warmth, continuity of parental love (nurture), Kagan: innate personality (nature)
- Nature creates nurture- environment and hereditary interact
What is heredity?
Genetic transmission of both mental and physical characteristics from one generation to another
What is environment?
Any influence on behaviour that is non-genetic
What is the diathesis-stress model?
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- Behaviour is caused by a biological/ environmental vulnerability, which is only expressed when coupled with a biological/environmental trigger (stressor)
- E.g: inheriting genetic vulnerability for OCD does not mean you always develop OCD but when combined with psych trigger, OCD is more likely to appear
What are epigentics?
- Change in genetic activity without changing the genes
- Occurs throughout life, caused by an interaction with the environment
- Aspects of our lifestyle/events we encounter, leave ‘marks’ on our DNA, which switch genes on and off
- Explains why factors, e.g: smoking, have lifelong effects even after stopping= changed the way genes are expressed
- Epigenetic changes may influence genetic codes of our children
What is nature?
- Refers to inherited influences/hereditary
- Early nativists (Descartes) argue all human characteristics are innate
- Psychological and physical characteristics are determined by bio factors
What is nurture?
- Refers to the influence of experience and the environment
- Empiricists (Locke) argue the mind is a ‘blank slate’ at birth, shaped by the environment
- Lerner identified different levels of the environment, e.g: prenatal factors (i.e. how physical/psych influences affect a foetus)
How are nature and nurture measured?
- Degree to which two people are similar (concordance) can be represented by a correlation coefficient
- Estimate of the extent to which a trait is inherited
- .01= genes contribute almost nothing to individual differences and 1.0= genes are the only reason for individual differences
What is the general hereditability figure for IQ?
Plomin= .5 for IQ. Means ½ a person’s intelligence is determined by genetics, and ½ by environment
Strength-
I- Research support from adoption studies
D- If adopted kid is more similar to adoptive parents= environment is biggest influence. If mores similar to bio parents= genetics dominate. Rhee and Waldman carried out meta-analsysis of adoption studies, and found genetic influences= 41% of aggression variance
E- Research can separate influence of nature/nurture
Limitation-
I- Nature and nurture cannot be separated
D- Plomin- people created their own nurture by actively seeking environments that are appropriate for their nature. Naturally aggressive children likelt to feel more comfortable with kids who show simialr behaviours (niche-picking)
E- Doesn’t make sense to look at evidence of each separately
Strength-
I- Support for epigenetics
D- WW2 (1944)- Nazis blocked food distribution to the Dutch and 22,000 died of starvation (Dutch hunger wainter). Susser and Lin- women who fell pregnant during the famine had low birth weigth babies, who were 2X as likely to develop schizophrenia
E- Supports view that experiences of previous generations leave epigenetic markers that influence health of offspring
Strength-
I- Real world application
D- Nestadt= OCD is highly heritable= .76. Informs genetic counselling- important to understand that high heritability does not mean development is inevitable . Those with high risk of OCD (risk factors) can receive advice about likelihood of developing disorder, and how to prevent it
E- Shows the debate is not only theoretical, but important at practical level, to understand the interaction
Evaluation extra-
I- Implications of the debate
Strength-
D- Natvists suggest ‘anatomy is destiny’- genetic make-up determines characteristics, with little environmental input. Extreme stance= controversy- used by Hitler/Nazis- application of Darwin’s selective breeding to create a ‘master race’
Limitation-
D- Empiricists suggest behaviour can be changed by altering environmental conditions. Behaviour shaping= practical application in therapy. Desirable behaviours are selectivelt reinforced, undesirable behaviours= punished/ignored
E- Suggests both positions, taken to extremes, may have -ve consequences, so a moderate, interactionist positon is preferred
