The hormones that make women able to bear children and suckle them are the same hormones that make them emotional and emotionally unreliable once a month.  

The American public recognizes the differences between men and women, which accounts for, what, 50 years of "equality," yet only 20 percent of Congress are women, 10% of states have female governors.  The places where we see in equal numbers of leadership positions is when there is appointment, not election, e.g., colleges and in many workplaces.  Quotas do not make women the same as men.