Robert Plomin

American geneticist

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July 1, 2026

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Robert Plomin is an American geneticist known for his work in behavior genetics. This field studies how an organism's genetic makeup influences its behavior, exploring the interplay between heredity and environment.

Plomin's research, particularly on twins and adopted children, suggests that genetic factors account for approximately 50 percent of the variation in behavioral differences within a population. His findings indicate that for traits like sociability, impulsiveness, and emotional sensitivity, identical twins show twice the similarity compared to fraternal twins, with shared family environments contributing very little to these similarities. This highlights the significant role genetics plays in shaping personality and behavior.12

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personality
Genetic aspects
…States, behaviour geneticists such as Robert Plomin report that, in behaviours describable as sociability, impulsiveness, altruism, aggression, and emotional sensitivity, the similarities among monozygotic (identical) twins is twice that among dizygotic (fraternal) twins, with the common environment contributing practically nothing to the similarities. Similar findings are reported for twins reared…
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…States, behaviour geneticists such as Robert Plomin report that, in behaviours describable as sociability, impulsiveness, altruism, aggression, and emotional sensitivity, the similarities among monozygotic (identical) twins is twice that among dizygotic (fraternal) twins, with the common environment contributing practically nothing to the similarities. Similar findings are reported for twins reared…
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