Honestly? Forging for berries and tending to children probably didn't require as quick of reflexes as hunting did. Since those were the traditional roles for millennia, men developed better reflexes, spatial awareness, and physiques to better hunt. On the other hand, women developed much better eye sight (women can see [i]way[/i] more colors than men) which helped with foraging and identifying vegetation, and they also gained wider hips and a higher body fat content for better child rearing. It's not a bad thing that men and women are better at different things.