[collyw]

"If someone is naive enough to believe that boys and girls have innately different interests, then so be it."

Its been shown that male monkeys prefer boys toys while females prefer girls toys. No cultural conditioning required.

http://animalwise.org/2012/01/26/born-this-way-gender-based-...

[Kalium]

Before someone jumps in with the notion that monkeys have culture too, it should be noted that monkeys have not developed the wheel. Thus, they are unlikely to have defined gender roles for wheeled toys.