[aruanan]

Boys will compete just for the sake of it, but girls will not waste effort on competition unless it pays, a Canadian study has revealed.

Note what this means but what the article doesn't state: boys will dig in and compete no matter what. All they have to do is to believe that an arena of competition exists. This explains why men are more likely to be involved in sports, combat, business, (and crime). Girls will limit their participation by their own concepts of what will pay off. Since one's own concepts of what will pay off are necessarily limited by one's experience, intelligence, ability to predict, (and fantasies about how it's all going to pan out) this would explain why so many of them marry absolute bums. It would also explain why some marriages work so well: a woman with superior abilities to predict what will or won't pay off gets hitched up with a guy who will pursue the goal even if it means crawling on broken glass.

[blam]

"a woman with superior abilities to predict what will or won't pay off gets hitched up with a guy who will pursue the goal even if it means crawling on broken glass."

Behind every successful man is a woman. (pushing?)

[dennisw]

It would also explain why some marriages work so well: a woman with superior abilities to predict what will or won't pay off gets hitched up with a guy who will pursue the goal even if it means crawling on broken glass.

Works the other way 'round too. Superior men want a women with good upbringing, ability to carry, nurture and instruct babies/children, and good genetics.