I'm not really sure how a study about monkeys has any relevance to whether humans have engrained gender roles. People are cognitively far more complex and nature vs. nurture when it comes to gender is not really as decided as it might seem.
Surprisingly that might work - "Several animal studies have shown that hormonal manipulation can reverse sex-typed behavior. When researchers exposed female rhesus monkeys to male hormones prenatally, these females later displayed male-like levels of rough-and-tumble play."