First 272 words of the document:
Evaluation of genetic factors influencing intelligence test performance
twin studies- confounding variable of environment- adoption studies better
environment can influence how gees are expressed. E.g. breastfeeding can
interact with the C version of the gene FABS2 (fatty acid denaturise) to increase
intelligence slightly. Children with weak G version didn't show an increase. This
shows that nature can nurture both influence intelligence.
identical genes but have very similar environments so it is hard to see what role
genes play. Genes could account for 72% of the variance in intelligence but
separating twins from their mothers could cause short term effects which could
/ Polman- good form accounts for 30% of bright people and 16% of average
intelligence. This suggests that intelligence is influenced by genetic factors but
intelligence is likely to be influenced by a whole range of genes. Other research
has been unable to replicate the study therefore we are uncertain that the gene
influences intelligence as the study is unreliable.
Turkenheimer shows that the same gene can have different effects upon
intelligence in different cultures. E.g. genes have more of an effect on children
from a poor background so it is difficult to generalise and is therefore culturally
bias so we can't generalise the 50% role of genes to other cultures.
evidence from the twin studies suggests that genetic factors play a direct role in
determining intelligence. Turkenheimer and Caspi's FABS2 study shows
environmental factors are involved so genetic theory s therefore deterministic.