The Heritability of Personality Factors in Chimpanzees (Pan troglodytes)

Human personality and behavior genetic studies have resulted in a growing consensus that five heritable factors account for most variance in human personality. Prior research showed that chimpanzee personality is composed of a dominance-related factor and five human-like factors—Surgency, Dependability, Emotional Stability, Agreeableness, and Openness. Genetic, shared zoo, and nonshared environmental variance components of the six factors were estimated by regressing squared phenotypic differences of all possible pairs of chimpanzees onto 1 − Rij, where Rij equals the degree of relationship and a variable indicating whether the pair was housed in the same zoo. Dominance showed significant narrow-sense heritability. Shared zoo effects accounted for only a negligible proportion of the variance for all factors.