Leigh Dayton, Science writer | September 22, 2009
SINGLE mothers are up against it -- not just in terms of time, money and the logistics of life but also against thousands, if not millions, of years of evolution.
According to American emeritus professor of anthropology Sarah Blaffer Hrdy, there was "no such thing as a single mother" in the Pleistocene epoch, which covered almost 2.5million years and ended 12,000 years ago.
Professor Hrdy, for more than two decades, has investigated parenting in a host of animals, including monkeys, apes and people. She said a single mother in the Pleistocene age "would have died, the baby would have died".
The author of the book Mothers and Others: The Evolutionary Origins of Mutual Understanding is in Australia for this week's Charles Darwin Symposium in, of all places, Darwin.
She argues that "shared care" evolved in the distant past, along with the intellectual skills that gave ancestral humans an edge.
According to Professor Hrdy, humans are the only primate that allows anyone other than the mother to hold and feed an infant. Without such mutual support, highly dependent, slow-maturing human infants could not survive.
"There's a lot of shared provisioning in other animals, but not in any other ape," she claimed.
The result is a species that functions best when everyone chips in with the childcare.
"Shared care is natural," Professor Hrdy said. "In hunting and gathering and traditional societies, infants are cared for mostly by older siblings, aunts, grandmothers, fathers and male cousins."
Professor Hrdy claimed there were lessons for the fragmented families of the modern world. For one, she said, children should always be picked up when they cried.
"It doesn't make it more spoiled," she said. "A more secure baby will cry less later in life."
Another lesson from evolution was that the more "alloparents" -- friends and family to help with the baby -- the better. That's why "daycare is here to stay", she said, adding that the carers should be consistent.
Even women with partners might feel swamped, but Professor Hrdy had a tip.
"There's a vast untapped resource out there called paternal care," she said.
"Men who are close to pregnant women and babies have an amazing transformation."
Specifically, testosterone goes down while two hormones, prolactin and oxytocin, which promote bonding, go up.
And for couples with young children and limited "alloparents", Professor Hrdy suggested building "artificial families", from sharing the load with parents in the youngster's play group to moving into a home with communal space.