Your hypothesis may be flawed. The female workforce is higher than the man workforce.Sowhat ifgendered occupational roles WERE biologically defined. Why is it that the 'male jobs' just happen, on average, to pay more? I mean, there's approximately the same supply of labor on both sides of the gender scale, so it's not a supply issue.
Since I'm not allowed to say patriarchy, I guess I challenge one of you to come up with a logical alternative hypothesis.