It doesn't take a Ph.D. from Harvard to change a diaper. In fact, "Harvard Ph.D.'s shouldn't be nannies," according to a few of my bosses, scientific colleagues, and family members. They have told me, sometimes gently and sometimes bluntly, that I should not be spending my valuable time as the primary caregiver for my four sons. I should, they tell me, be using my degree and my scientific knowledge out there in the working world.