Parents should carry their babies upright instead of pushing them around in prams because it aids their development, a leading US scientist has claimed.
Jared Diamond, the Pulitzer Prize-winning scientist, said children could benefit from basic parenting methods which have been abandoned in the west but are still used in more traditional societies around the world.
Indigenous people living in the African rainforest, for example, use a variety of behaviours which developed over hundreds of thousands of years of human history, but which have recently become "unfashionable" in the modern world, he said.
In his new book, The World Until Yesterday, Diamond argues that readopting traditional child-raising methods could help parents raise children with good qualities like confidence and curiosity.
"It would be impossible, illegal, or immoral to carry out rigorous controlled experiments on Western children, in order to test outcomes of different child-rearing methods," he said.
But a huge variety of different methods has in effect already been tested by natural experiments: different societies have been raising their children differently for a long time, and results can be seen.
"Carrying your baby upright and facing forward may result in a more self-assured child," he said.
Diamond spent 50 years working with traditional societies in New Guinea, and other western researchers have closely studied other groups including the Pygmies of African rainforests and the Piraha Indians of Brazil.
"We are struck by how emotionally secure, self-confident, curious, and autonomous the members of those small-scale societies are, not only as adults but already as children," he said.
"That`s surely the result of how they are raised as children. I think that we can foster those admirable qualities in our own children, by emulating some hunter-gatherer child-rearing practices," Diamond said.
Techniques such as quickly comforting a crying baby, allowing them to sleep with their parents, having a lot of physical contact with them and carrying them upright and facing outward can help their development, he said.
"Much anecdotal evidence indicates that such techniques can also benefit our own children. We humans lived as hunter-gatherers for hundreds of thousands of years," he said.
"We moderns can learn from what worked well for such a long time. It is only relatively recently that some of these traditional child-rearing practices became unfashionable. I suggest that it`s time to consider some of them seriously again," he added.