the stereotypical personality profile of a typical only child differs consistently from the stereotypical profile of those who have siblings on 23 out of the 30 NEO-PI-R subscales.
These differences between stereotypical personality profiles do not reflect self-descriptions because the self-rated personality profiles made by only children coincide almost perfectly with the self-rated personality profiles of those who have brothers or sisters. The multiple children stereotype reflects rather accurately both the mean normative and the socially desirable personality profile.