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 one8(11), e80945.

10 thoughts on “Chimps abandon social norm for prizes

    • It might just be a matter of intelligence. Many animals don’t adopt new strategies because they don’t realise they’re more efficient. However, I think this study shows this isn’t the case with conservatism in chimps. They may realise a new strategy is better, but for some reason still don’t adopt it.

      • From an evolutionary game theory perspective you wouldn’t want to adopt a new strategy until it has been demonstrated non-lethal to its user in the long term. This is a higher ratification standard than mmm-tastes-good. For humans, having an conceptual framework of how the world works allows us to place limits on the potential risks of new stuff and so *may* swing us a little towards being early adopters. I guess intelligence has its benefits at times. OTOH just about every advance in human technology has induced sufficient cortisol release to require the creation of explaining stories – death rays emanating from mobile phones and the like – which is, I suppose, evidence that we are actually a species of ape.

        (And I do like the jokes, and the metajokes.)

        • It would be interesting to try and isolate these two factors. Perhaps increase the risk of the more efficient strategy, see where the cut off is. And in another experiment, obfuscate the result of actions a bit and see if chimps can (a) still figure it out and (b) whether they still plump for the new strategy.

      • Nietzsche’s Will to Power might explain that. Those in possession of power/authority (the elder chimps) feel threatened by new behaviour; behaviour that is different to, or even perhaps contradictory to the system from which they derive (and enjoy) their power.

  1. If I’m not mistaken, most animals who use tools and have good problem solving skills (chimps, crows etc.) have this same problem. One they develop a strategy that works they are lothe to change it. Since, in the wild, chimpanzees learn their tool using skills from their mothers when they are young and impressionable, it would be hard for them to change. But, I guess, only seeing is believing when you haven’t yet developed good communication skills.

    • I know capuchin monkeys are unwilling to switch strategies once they have learned one, but this seems to be because they just don’t understand why their method is successful. If you remove the obstacle they’re using the strategy to overcome they still use the strategy.

  2. Pingback: Kevin D. Williamson: ‘Politicians Steer the Economy Like Chimps Fly Rockets’ | pundit from another planet

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