Would you gamble on a safe bet for the promise of something more? Would you risk losing everything for the possibility of greater rewards? In psychological experiments, humans tend to play it safe when we stand to gain something – we’re more likely to choose a certain reward over a larger but riskier one. Now, we’re starting to understand how our two closest relatives deal with risk – bonobos, like us, tend to be risk-averse while chimpanzees usually play the odds.

Sarah Heilbronner from Harvard University studied the attitudes of five chimps and five bonobos to risky decisions. All the animals had been born in captivity in the Liepzig Zoo, Germany and were fed well on a regular