Behavior Genetics

, Volume 14, Issue 6, pp 579–585 | Cite as

Effects of inbreeding on Raven Matrices

  • Nirupama Agrawal
  • S. N. Sinha
  • Arthur R. Jensen


Indian Muslim school boys, ages 13 to 15 years, whose parents are first cousins, were compared with classmates whose parents are genitically unrelated on the Raven Standard Progressive Matrices, a nonverbal test of intelligence. The inbred group (N=86) scored significantly lower and had significantly greater variance than the noninbred group (N=100), both on raw scores and on scores statistically adjusted to control for age and socioeconomic status. Genetic theory predicts both of these effects for a polygenic trait with positive directional dominance.

Key Words

inbreeding depression intelligence Raven matrices heritability polygenic theory 


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Copyright information

© Plenum Publishing Corporation 1984

Authors and Affiliations

  • Nirupama Agrawal
    • 1
  • S. N. Sinha
    • 1
  • Arthur R. Jensen
    • 2
  1. 1.Department of PsychologyUniversity of RajasthanJaipurIndia
  2. 2.School of EducationUniversity of CaliforniaBerkeley

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