The Heritability Of Temperament Flashcards
What is temperament?
Individual differences in emotion, activity level and attention. Lots of variation in how children express their emotions. Two approaches:
- Between-person approach (Thomas & Chess) = classified children’s temperament into 3 groups: easy, difficult, slow-to-warm-up.
- Within-person approach (Rothbart et al.) studied how infants express emotions into different contexts = fear, distress/anger, attention span, activity level, smiling & laughter.
What is the ‘nature versus nurture’ debate?
Children vary significantly in their reactions & expression of emotion. When measuring this it displays bell curved distribution. When researching this area interested in individual differences within the population.
What is the role of biological families?
Parents provide genetic and environmental influences for their child. Passing genetic info from parent to children is important in explaining innate nature of temperament. In studies of biology families, it is not possible to disentangle the effects of genetics (nature) and environment (nature).
What are genetically informative research designs?
Because cannot disentangle the effects of genetic and environmental factors, the solution is twin & adoption designs.
What is involved in an adoption design?
In adoption biological parents provide genetic influence, adoptive parents provide environmental influences. If see similarities between adoptive parents and children can put down to environmental influences. If similarity between biological parent and children can put down to genetic influences.
What are the limitations of adoption studies?
- Adoptees are not placed randomly into adoptive families - tend to be chosen to provide environments that are low-risk.
- Adoption studies may not be generalisable to the population at large - small sample sizes.
- Prenatal influences are not taken into account (e.g. whether the mother smokes, what she eats etc.)
What is involved in a twin design?
Studies dizygotic twins and monozygotic twins. Compare resemblance of these twins. Allows a rough estimate of separating genetic and environmental contribution to a trait.
What is heritability?
Heritability = genetic influence = the proportion of variance in a population attributable to genetic differences between people. Heritability estimates apply only to a particular population at a particular time. Does not account for interplay between genetic and environmental factors.
What is an example of a twin study of child temperament?
Lemery-Chalfant et al. (2013). 807 pairs of twins, mean age of 8. concluded parents temperament can influence a child through genetic transmission and through home environment they create.
What are limitations of twin design?
Equal environments assumptions (the assumption that environments are similar for identical and fraternal twins, monozygotic twins share similar environments), twin studies may not be generalisable to the population at large (twins more susceptible to prenatal trauma), MZ twins may not be 100% genetically identical.
