Participants from both species were presented with the opportunity to obtain food from one of two out-of-reach boards. To get food from the first board, participants had to pull a set of ropes on their own to move the food board closer. To access food from the second board, participants had to work collaboratively with a conspecific partner, pulling the set of ropes simultaneously with their partner to access the food. Participants from both species were then given a choice between the two boards: did they want to work with a partner or would they prefer to operate the board by themselves? The authors found a big difference across the two populations. Children preferred to obtain food using the collaborative board, choosing the teamwork option about three quarters of the time. Chimpanzees, in contrast, performed at chance; they were indifferent to whether another conspecific worked with them to solve this problem, suggesting they're not as motivated to seek out opportunities to work together.To explore the chimps motivation in more detail:
They presented chimpanzees with a similar foraging problem to that of the previous study, but varied the payoffs across the solitary and collaborative boards. In their first study, they observed that chimpanzees show a striking preference to work by themselves when the pay-offs are equated across the two boards. They then changed the pay-off structure in the next study, allowing chimpanzees to earn more food when they worked with a partner. Only when the relative pay-off from the collaborative board was increased did chimpanzees show the kind of preference that children showed for foraging collaboratively. Chimpanzees, it seems, need a little something extra to work in a team; children are motivated to do it for free.