Sources of human psychological differences: the Minnesota Study of Twins Reared Apart.

@article{Bouchard1990SourcesOH,
  title={Sources of human psychological differences: the Minnesota Study of Twins Reared Apart.},
  author={Thomas J. Jr. Bouchard and David T. Lykken and Matt McGue and Nancy L. Segal and Auke Tellegen},
  journal={Science},
  year={1990},
  volume={250 4978},
  pages={
          223-8
        }
}
Since 1979, a continuing study of monozygotic and dizygotic twins, separated in infancy and reared apart, has subjected more than 100 sets of reared-apart twins or triplets to a week of intensive psychological and physiological assessment. Like the prior, smaller studies of monozygotic twins reared apart, about 70% of the variance in IQ was found to be associated with genetic variation. On multiple measures of personality and temperament, occupational and leisure-time interests, and social… 
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