What is common between toddlers and chimps? Both tend to copy actions of their peers.
"I think few people would have expected to find that two-year-olds are already influenced by the majority," said Daniel Haun of the Max Planck Institutes for Evolutionary Anthropology and Psycholinguistics, the journal Current Biology reports.
Earlier studies revealed that children are sensitive to peer pressure already at preschool age. Researchers wanted to know whether the majority influences social learning at an even earlier age and in other primate species as well, according to a Max Planck statement.
Haun's team built a box with three holes, each a different colour. The box delivered a treat only when a ball was dropped into one of those three, coloured holes.
Toddlers, chimps and orangutans unfamiliar with the box were then allowed to watch as four of their same-species peers interacted with the box. The majority of those peer demonstrators had been trained to favour one colour over the others.
When the two-year-old and chimpanzee observers got their turn, they tended to favour the hole favoured by their friends. That's in contrast to orangutans, which chose the holes at random.
While the findings might leave some parents in dismay, majority rule probably does have its advantages, evolutionarily speaking.
"The tendency to acquire the behaviours of the majority has been posited as key to the transmission of relatively safe, reliable, and productive behavioral strategies," Haun said.