Sex differences in personality scores
"Many significant, but mostly small, differences"
Behaviour geneticists contend that the rough rule of thumb when it comes to the determinants of adult personality and other traits is 50–0–50, that is, roughly 50% of the variance in personality, behaviour, and other traits is heritable (influenced by genes), roughly 0% by the shared environment (what happens within the family and is experienced similarly by all siblings), and roughly 50% by the non-shared environment (what happens inside and outside the family not shared by siblings)