Abstract
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.
Keywords: Eysenck personality questionnaire, Lie-scale, Extraversion, Neuroticism, Psychoticism, Birth weight, Birth
length, Birth head-circumference