Reply #5: Do you believe the monkeys in the study are also brainwashed,

[Occam Bandage]

or that at some point in the evolutionary tree, that primates lost their innate gender-based toy preferences? The latter seems possible, but I think it's unlikely. I believe that there is some innate gender-based preference towards certain types of toys, but that it serves only as one factor out of many; gender certainly does not dictate toy preference in human children.