In the present study, we investigated the existence of an effect of measuring personality at different levels on parent-offspring correlations and subsequently on familial aggregation estimates. Personality was conceptualized at four levels: specific reactions level, domain level, higher-order factor level and general factor of personality. FFPI (Hendriks et al., 1999) was administered to a sample of 115 adolescents and their parents. Father-offspring correlations, mother-offspring correlations and regression of offspring on midparent score were computed for 100 specific reactions, 5 domains (Extraversion, Agreeableness, Conscientiousness, Emotional stability and Autonomy), 2 higher-order factors (α and β) and 1 general factor of personality. At the specific reactions level, we can only say that there is a trend indicating low heritability (Mdn = 0.13). At the domain level, genetic effects accounted for 26 to 34% of the phenotype variance. The same proportion of genetic effect on phenotype was found at the higher-order factor level (28 to 35%) and at the general factor level (33%). To summarize, personality is moderately and about equally heritable (26-35%) at domain level, higher-order factor level and general factor of personality level but less heritable at the specific reactions level.

FFPI, family study, personality, higher-order factors, heritability