Genetic Variance in Adaptive Personality Traits*

The Cognitive Foundations of Personality Traits

“…The hypothesis was that traits with a relatively larger genetic determination would be related to more meaning variables than traits with a relatively smaller genetic determination. Presentation of the hypothesis was made possible by the existence of two independent studies assessing the heritability of CPI scales (Gottesman, 1966;Loehlin & Nichols, 1976). Because the hypothesis dealt with relative degrees of genetic determination, we felt that it could be stated and tested regardless of whether one assumes a greater (H. Eysenck, 1973) or a lesser role (Loehlin & Nichols, 1976) for genetics in human personality.…”

Platelet Monoamine Oxidase Activity Correlates with Social Affiliative and Agonistic Behaviors in Normal Rhesus Monkeys

“…This appears to be the case with some behavioral traits, inferred from personality inventories in normal humans, which are similar to such behavioral items as sociaJ contact and alone evaluated in this study. "Sociability," "extraversion," and "person-orientation," have been found to be highly heritable (3,61,62) with genetic factors accounting for 60-80% of the within-family variance (63,64). With the exception of the extensive data associating "aggression" with sex differences and possibly with some chromosomal abnormalities (65), there are no studies demonstrating genetic factors associated with aggression in humans (66), possibly because of the difficulties in defining, identifying, and measuring aggression in normal humans (67).…”

Genetic and Rearing Environmental Influences on Adult Personality: An Analysis of Adopted Twins Reared Apart

“…The CPI has been used m a number of behavioral genetic studies of personality (Gottesman, 1966, Hom, Plomin, & Rosenman, 1976, Loehlin, 1986, Loehlin & Nichols, 1976, Nichols, 1966 Findings with the CPI have been remarkably consistent and very similar to those obtained with other personahty mventones The mean CPI scale score correlation of 45 reported here for the MZA twins is comparable to the mean CPI scale conelations reported in two independent studies of reared-together MZ twins Loehhn and Nichols (1976) reported an average CPI scale conelation of 49 m a sample of 490 pairs of adolescent MZ twins Hom et al (1976) reported an average of 44 m a sample of 99 pairs of MZ twins age 45 to 55 years Similar results have been reported using other personality inventories and m other Westem countries (Floderus-Myrhed, Pedersen, & Rasmuson, 1980 Regardless of age (adolescent or adult) or reanng status (together or apart) the personality scale scores of MZ twins are correlated between 45 and 50…”