Childbearing and child rearing consume so much energy that the women who do become mothers can quickly become swallowed up by that daunting task - if not outright killed by it. Thus, maybe we need extra females, women on the sidelines with undepleted energies, who are ready to leap into the mix and keep the tribe supported...
Childless women have always run orphanages and schools and hospitals. They heal the sick and teach the arts and often they become indispensable on the battlefield of life. Literally, in some cases. (Florence Nightingale comes to mind.)
Such childless women - let's call them the "Auntie Brigade" - have never been very well honored by history, I'm afraid. They are called selfish, frigid, pathetic.
Here's one particularly nasty bit of conventional wisdom circulating out there about childless women that I need to dispel here, and that is this: that women who have no children may lead liberated and happy and wealthy lives when they are young, but they will ultimately regret that choice when they reach old age, for they shall all die alone and depressed and full of bitterness. Perhaps you've heard this old chestnut?
Just to set the record straight: There is zero socio-logical evidence to back this up. In fact, recent studies of American nursing homes comparing happiness levels of elderly childless women against levels of women who did have children show no pattern of special misery or joy in one group or the other. But here's what the researchers did discover that makes elderly women miserable across the board: poverty and poor health. Whether you have children or not, then, the prescription seems clear: Save your money, floss your teeth, wear your seatbelt, and keep fit - and you'll be a perfectly happy old bird someday."
-- Elizabeth Gilbert, Committed, 2010