He said: "It would be impossible, illegal, or immoral to carry out rigorous controlled experiments on Western children.
"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 we can see the results.
"I've worked with traditional New Guinea peoples for 50 years. Many other Westerners have worked with other traditional societies. We are struck by how emotionally secure, self-confident, curious and auto-nomous the members of those societies are, not only as adults but already as children.
"That's surely the result of how they are raised. I think we can foster those admirable qualities in our own children, by emulating some hunter-gatherer child-rearing practices."
In his book, The World Until Yesterday, he says comforting a crying baby within seconds, letting them sleep next to their parents, having lots of physical contact and carrying them upright and facing outwards can aid development. He said: "Carrying your baby upright and facing forward may result in a more self-assured child."