>> myth is that the differences are innate or "biological"

erm...please read

1. Genomic differences between developing male and female brains in the womb-- http://www.sciencedaily.com/releases/2015/02/150203190223.ht...

and if you still feel that somehow humans try to gender stereotype whilst the fetus are still in the wombs, then read this also-

2.Sex differences in rhesus monkey toy preferences parallel those of children-- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2583786/