Twin Studies of General Mental Ability

Twin studies are a vital source of information about genetic and environmental influences on general mental ability. The classic twin design—comparison of the relative similarity between monozygotic (MZ) and dizygotic (DZ) twins— is a simple and elegant approach to estimating the effects of genes and experience on developmental traits. However, while this method was considered state of the art in behavioral genetics in the 1960s and 1970s, it is now only one of many more sensitive and sophisticated twin designs. Twin research on behavioral and medical traits, in general, and on intelligence, in particular, has advanced at an impressive rate.


Twin Pair Twin Study Monozygotic Twin General Intelligence Mental Ability 


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© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Department of PsychologyCalifornia State UniversityFullertonUSA
  2. 2.Centre for Cognitive Ageing and Cognitive Epidemiology and Department,of Psychology,University of EdinburghUK
  3. 3.Department of PsychologyUniversity of MinnesotaMinneapolisUSA

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