Tell me it's not throw-up material, this sudden parade of glamorous career women arguing across the front pages about the best way to birth, suckle and rear their young. Next it'll be the diaper diaries, and we'll all be expected to hang impatiently on the cloth v disposables dialectic, parsing the contents like ancient seers. Anyone would think today's thirtysomethings were the first ever to achieve parturition.

But there is something interesting about these Mummy Wars, all the same. It's this. The root from which they so vigorously sprout is the cleft stick in which feminism has got itself thoroughly, perhaps irreparably, wedged.

Insecurity is the soil. You don't hear men angsting in public over whether they're even halfway decent fathers. If paternal guilt exists, they're all very grown up about it. Yet we're supposed to believe that these traits are learnt, not innate. Learnt from whom? Well, from teachers (oops, mostly female). Mothers (even oopser). OK, from big, bad, paternalistic society.

Insecurity is the soil of the Mummy Wars but behaviourism is the root, or at least the cleft stick that holds it.

Feminism has long committed to behaviourism in order to deny innate brain-difference, arguing it's all nurture, no nature. Why? Because anything else makes femaleness a disadvantage, out in the world beyond domesticity. The minute you allow difference - say, ''males are more driven'' - you make non-maleness second-rate.