Children learn a great deal by imitating adults. A new study of Australian preschoolers and Kalahari Bushman children finds that a particular kind of imitation -- overimitation, in which a child copies everything an adult shows them, not just the steps that lead to some outcome -- appears to be a universal human activity, rather than something the children of middle-class parents pick up. The work helps shed light on how humans develop and transmit culture.

Scientists "have been finding this odd effect where children will copy everything that they see an adult demonstrate to them, even if there are clear or obvious reasons why those actions would be irrelevant," says psychologist Mark Nielsen, of the University of Queensland in Australia. "It's something that we know that other primates don't do." If a chimpanzee is shown an irrelevant action, they won't copy it -- they'll skip right to the action that makes something happen.

But it's not clear that the results found in child psychology research apply to all people, Nielsen says. This research is usually done with children who live in Western cultures, whose parents are well educated and middle to upper class. And these parents are constantly teaching their children. But parents in indigenous cultures generally don't spend a lot of time teaching. "They may slow what they're doing if the child is watching, but it's not the kind of active instruction that's common in Western cultures," says Nielsen. So he teamed up with Keyan Tomaselli, an anthropologist at the University of KwaZulu-Natal in Durban, South Africa, who has worked for decades in Bushman communities in southern Africa. Their study is published in Psychological Science, a journal of the Association for Psychological Science.

For the experiments, the children were shown how to open a box -- but in a complicated way, with impractical actions thrown in. For example, the adult would drag a stick across a box, then use a stick to open the box by pulling on a knob -- which is a lot easier if you just use your fingers. Most of the children copied what the adults did, even if they'd been given the opportunity to play with the box first and figure out how it worked. This was just as true for Bushman children as for the Australian children.

But aren't the children just following the rules of what appears to be a game? "That kind of is the point," says Nielsen. "Perhaps not a game, but certainly, when I demonstrate the action, it's purposeful. So from the mind of a child, perhaps there's a reason why I'm doing this." This willingness to assume that an action has some unknown purpose, and to copy it, may be part of how humans develop and share culture, he says. "Really, we see these sorts of behaviors as being a core part of developing this human cultural mind, where we're so motivated to do things like those around us and be like those around us."