Big babies may have helped define the shape of modern human societies: Study

Large babies shaped the development of modern human societies, according to a new study.

The research revealed that human babies weigh proportionately more at birth than the newborns of any other primate species and this may have influenced the development of our society.

A baby ape weighs an average of 3% of what its mother weighs this doubles to 6% for baby humans.

Our earliest human ancestors most likely had big babies too and this could have helped define the shape of modern human societies, research has suggested.

'Humans are strange, in all sorts of ways. We walk upright on two legs and our newborns are helpless. Our babies are unusually large. They have unusually large heads; they have unusually large bodies compared to other primates," the Daily Mail quoted Jeremy DeSilva, an anthropologist at Boston University, as saying.

In order to find out whether species that were around millions of years before humans, such as Australopithecus, also weighed more, DeSilva decided to use adult skills to estimate the newborn's skull size.

Using this method, he analysed a dozen Australopithecus skulls.

"So once you have the size of the head, there is what researchers have called "the 12% rule.

"The 12% rule says that the brain represents 12 per cent of the total body weight. It's not exactly 12% - in fact, in the apes it tends to be more like 10%," he told radio station NPR.

Even allowing for this difference, DeSilva concluded that Australopithecus newborns were much closer to being 6% of their mother's weight than to 3%, like in apes.

He believes that rearing large babies has had a significant influence on human culture, even helping to stabilise communities.

The study was published in the journal PNAS.