An association of adult personality with prenatal and early postnatal growth: the EPQ lie-scale

BACKGROUND Recent studies have noted differences in social acquiescence and interpersonal relations among adults born preterm or with very low birth weight compared to full term adults. In addition, birth weight has been observed to be negatively correlated with lie-scale scores in two studies. We attempted to replicate and extend these studies by examining young adult lie-scale scores in a Danish birth cohort. METHOD Weight, length and head circumference of 9125 children from the Copenhagen Perinatal Cohort were measured at birth and at 1, 3 and 6 years. A subsample comprising 1182 individuals participated in a follow-up at 20-34 years and was administered the Eysenck Personality Questionnaire (EPQ) which includes a lie-scale (indicating social acquiescence or self-insight). Associations between lie-scale scores and weight, length and head circumference respectively were analysed by multiple linear regression adjusting for single-mother status, parity, mother's age, father's age, parental social status, age at EPQ measurement, intelligence, and adult size. RESULTS Male infants with lower weight, length, and head-circumference at birth and the following three years grew up to have higher scores on the lie-scale as young adults. Most of these associations remained significant after adjustment for the included covariates. No associations were found for females. Analyses were also conducted with neuroticism, extraversion and psychoticism as outcome variables, but no significant associations were found for these traits after adjustment. CONCLUSIONS The findings replicate and extend findings from previous studies suggesting that size at birth and during the first three years of life is significantly associated with social acquiescence in adult men. They highlight the potential influence of prenatal and early postnatal development on personality growth and development.