Sources of Human Psychological Differences: The Minnesota Study of Twins Reared Apart

• DOI: 10.1126/science.2218526
• Publication Date: 2006-10-05T22:10:14Z
• Authors: Thomas J. Bouchard; David T. Lykken; Matthew McGue; Nancy L. Segal; Auke Tellegen
• Keywords: Dizygotic twins; Affect; Monozygotic twin; Dizygotic twins; Nature versus nurture; Behavioural genetics

Since 1979, a continuing study of monozygotic and dizygotic twins, separated in infancy reared apart, has subjected more than 100 sets reared-apart twins or triplets to week intensive psychological physiological assessment. Like the prior, smaller studies about 70% variance IQ was found be associated with genetic variation. On multiple measures personality temperament, occupational leisure-time interests, social attitudes, apart are as similar together. These findings extend support those from numerous other twin, family, adoption studies. It is plausible hypothesis that differences affect largely indirectly, by influencing effective environment developing child. This evidence for strong heritability most traits, sensibly construed, does not detract value importance parenting, education, propaedeutic interventions.