Thomas Bouchard’s Research on Identical Twins Reared Apart Reveals a Surprising Conclusion
Research on identical twins reared apart revealed a surprising conclusion: siblings are genetically identical, but can still be extremely different. Their upbringings and personalities are the same, but they may have experienced a different environment. Researchers from the University of Minnesota studied 60 pairs of identical twins and discovered that they displayed the same social attitudes and personality traits.
The study was led by Thomas Bouchard, a professor of psychology at the University of Minnesota. He was able to secure the funding necessary to conduct the study and attract as many twins as possible. The research lasted for 20 years.
In the early years of the study, researchers faced fierce criticism and hostility from the scientific community. They were accused of rigging the study to benefit their own interests. They were also accused of data fixing. During that time, the study produced relatively few peer-reviewed papers. The results were mostly presented in books and in news reports. As a result, the controversy over the research has faded in recent years.
Despite the preliminary findings, scientists are intrigued by the resulting results. The twins’ unpublished case histories and degree of separation were not analyzed by the researchers. As a result, the researchers assumed that MZA pairs were no more “reared apart” than TRA samples.
Interestingly, both of the adopted twins share some idiosyncrasies. Their personalities are similar, and they have the same names and hobbies. However, their social backgrounds are vastly different. Both of them had a Catholic grandmother, while their fathers were Protestant. The twins had the same tastes in clothes, and they had similar occupations.
Bouchard and colleagues analyzed the effects of contact between co-twins. They then compared the frequency of contact between co-twins to IQ scores. They concluded that the amount of contact between co-twins had no effect on the similarity of monozygotic twins reared apart.
Researchers continue to study the effects of rearing environments on the IQs of identical twins. In addition to personality traits, the researchers have also examined differences in the behavior and interests of monozygotic twins. They concluded that monozygotic twins were similar in IQ, but that they should be reared apart, rather than reared together.
The research team at the University of Minnesota has a team that is particularly knowledgeable about twins. The research team includes Irving Gottesman, a former collaborator of Shields in London who is now a professor at the University of Minnesota. Other members of the research team include David Lykken, who studied over 500 pairs of identical twins. They also include two identical twins, who are brothers by birth and live in different cultures.
Despite the differences in personality, identical twins reared apart show striking similarities in temperament and other personality variables. Their IQs and scores on standardized personality tests did not differ significantly from their matched counterparts. They also had similar expressive behaviors such as laughing, shyness, and facial expressions.