3.3 studies (biological) Flashcards
what’s was the aim of brendgen’s study?
to investigate aggression in mono and dizygotic twins to see the extent to which physical and social aggression can be explained by genetics and environmental
influences
what was the procedure for brendgen’s study?
- a twin study was used to calculate correlations of social and physical aggression by MZ and DZ twins
- 234 pairs of twins were selected from long lasting QNTS study
- study collected data on twins from 5 months to 6 years old
- 44 pairs MZ male, 50 pairs MZ female, 41 pairs DZ male, 32 pairs DZ female
- kindergarten teachers rates social and physical aggression of children on a 3 point scale
- social teacher quote: “says mean things and spreads rumours”
- physical teacher quote: “hits, bites and kicks others”
- children’s peers were shown 3 photos of classmates and nominated 3 children of the description that best fit them
what were the findings of brendgen’s study?
- only 20-23% of social aggression can be explained by genetics
- physical aggression is mostly explained by genetic factors
- correlation between social and physical aggression explained by shared genetic factors
what’s the conclusion of brendgen’s study?
- physical aggression is genetic and social aggression is environmental
- children could have aggression genes but learn that hitting others isn’t acceptable and adopt methods of being socially aggressive
what was the aim of hestons study?
to investigate whether nature or nurture was responsible for the development of schizophrenia
what was the procedure of heston’s study?
- participants in study were born to schizophrenic mothers and were put up for adoption from birth
- researchers ensured mothers had diagnoses of schizophrenia and no diseases
- 47 participants were chosen and matched with a control on sex and length of time in care
- data was collected from schools, hospitals and friend interviews
what were the findings of hestons study?
- rate of schizophrenia in those born to schizophrenic mothers was 10%
- those not born to schizophrenic mothers was 0%
what was the conclusion of heston’s study?
if your mother is schizophrenic, there’s a 10% chance you will be as well due to genetics
what’s a strength of heston’s study?
- high internal validity
- matched design was used (eg controlling gender)
- therefore, we can be confident that it is genetics that caused difference in 47 participants and not time in care
what’s a weakness of heston’s study?
- didn’t take into account other factors
- other variables such as drug use could have influenced mental health of children
- psychiatric status of father wasn’t checked
- therefore, the findings don’t provide a cause and effect conclusion for schizophrenia and genes
what’s an adoption study?
- groups of adoptees are observed and behaviours are correlated with their adoptive parents and natural parents
- shared environment with adopted parents but shared genes with natural parents
what’s a strength of adoption studies as a research method?
- removes extraneous variables of the environment
- only relation between a child and biological parent must be genetic as they’re not raised by them
- therefore, if there’s any similarities between child and biological parents it must be cos of genes
what’s a weakness of adoption studies as a research method?
- almost impossible to separate nature from nurture
- rare for children to be adopted into another family immediately so child may have spent time w biological family
- therefore, you can’t fully establish a cause and effect relationship between upbringing w adoptive parents and behaviours
