Chimps abandon social norm for prizes

Living in a big social group brings all sorts of advantages, but there are a few downsides. One of the oft forgotten ones is peer pressure. To secure relationships with others we often take actions not in our best interest; like splashing cash on fancy computers, consuming inappropriate amounts of alcohol and trying to force some humour in a science blog. Seriously, sometimes I make myself cringe. Although humans are very susceptible to peer pressure, we aren’t the only ones and many other social animals also find their behaviours dictated by society at large. Including our closest living relatives, the very social chimpanzees.

They’re also very conservative. And not in the sense that they believe it’s every chimp’s right to wield a spear. Rather, if they’ve learnt how to do something in the past they’re rather unwilling to do it a different way; even if the new way is much better. Chimps prefer to stick to the tried and true methods they already know, rather than adopting fancy new ways of cracking nuts. This may be one of the reasons that many of the most sophisticated, “human” chimp behaviours (like spear wielding) are rather rare. Most chimps just aren’t into the fancy new stuff. They prefer to kill bushbabies with their own two hands, like their grandfathers did in the days of yore.

Some researchers wondered if the two factors could combine to hold the chimps back. Might the behaviour of the majority prompt conservatism, by making chimps unwilling to use new techniques that were not the norm in their group. So they tested this in the obvious way: by setting up an experiment where most chimps were taught to get rewards one way, but a subset were taught to do it an easier way. Then they watched to see whether the peer pressure of everyone else behaving in a different way would force the minority chimps to abandon their strategy.

In fact, the opposite happens. Once the majority of chimps saw their strategy was a bit naff they quickly swapped to the minority strategy (although it take them a couple of days to come around to the alternate strategy). By the end of the study only 2 chimps out of the group were still using their original, inefficient strategy. It’s also worth noting that in an earlier experiment, where the two methods were rewarded equally neither group bothered changing strategy; even in the face of peer pressure.

So, short story short: chimp will abandon social norms if it means they get better prizes.

Reference

Van Leeuwen, E. J., Cronin, K. A., Schütte, S., Call, J., & Haun, D. B. (2013). Chimpanzees (Pan troglodytes) Flexibly Adjust Their Behaviour in Order to Maximize Payoffs, Not to Conform to Majorities. PloS one, 8(11), e80945.