Intelligence and genes Flashcards
Do genetics or the environment play a bigger role in determining intelligence?
Psychologists recognise that both genetics and the environment play a role in determining intelligence.
Research has indicated that around 40-80% of IQ is linked to genetics.
How do we test how intelligence develops?
- Twin studies.
- Adoption studies.
What did the Minnesota study of twins reared apart show?
Identical twins who spend their lives apart end up just as similar in intelligence as those who spend their lives together.
What is a limitation of many adoption studies?
The biological parent included is almost always the mother, therefore this could be a prenatal effect.
What does research into the effect of the environment on intelligence explore? (3)
- Birth order.
- Schooling.
- Biological variables such as breastfeeding and nutrition.
What did an experiment on birth order and IQ find?
The first born always had a higher IQ.
What did an experiment on the effect of schooling on IQ show? (2)
- The number of years in education can roughly be predicted from childhood IQ tests.
- Schooling and intelligence are intrinsically linked.
How do prenatal factors such as birth weight and breastfeeding effect intelligence?
Low birth weight children who were breast fed scored higher than children who had not been breast fed.
How do postnatal factors such as nutrition effect intelligence?
- Nutrition has been linked to larger brain sizes.
- Malnutrition has been linked to poor brain development.
What is heritability?
The proportion of variation of a characteristic attributable to genetic differences between members of that population.
What are two issues with estimating heritability?
- Heritability is an estimate, not a perfectly accurate statistic.
- Calculating heritability is a complex process and there is no consensus on exactly how it should be done.
