Aim- The aim of this experiment was to determine how genetics influence behaviour.
Study-It has been running since 1979 and this was done with the use of a cross cultural, longitudinal study. Bouchard et al. studied the monozygotic twins and dizygotic twins since infancy. To do this they had to conduct a four-part psychological review of Monozygotic twins reared together and monozygotic twins reared apart as well as dizygotic twins reared together and dizygotic twins reared apart.
Bouchard et al. had the twins complete 50 hours of testing and interviews to determine rates of intelligence. The concordance rates of these tests produced the findings that the identical twins reared together had a concordance rate of 86 per cent similarly the identical twins reared apart had a 76 per cent concordance rate. In comparison the dizygotic twins had a concordance rate of 55 per cent when reared together.
It was concluded by Bouchard et al. that the heritability can attribute to 70 per cent of intelligence meaning the other 30 per cent could be attributed to other factors.
This study is advantageous because we have the genetically identical comparison of the twins being raised together and apart as well as the comparison between the dizygotic twins therefore the study is able to support the hypothesis set at the beginning of the study. Another advantage is the variety of ages of the twins. Bouchard's experiment had a mean age of 41 years old at the start of the study unlike other studies conducted previously which were on children only.
However some limitations of the study include the use of media coverage to recruit participants which raises questions as to why some people would volunteer for this study. It also means that the study has a mixture of social...