Monkeys are savvier than human consumers when it comes to getting value for money, research has shown.
Psychological studies have demonstrated how easy it is to fool people into thinking that price reflects quality.
In tests, human volunteers consistently prefer the taste of wine poured out of an expensively labelled bottle to exactly the same wine with a cheap label.
But scientists found they could not make a monkey out of brown capuchins in quite the same way.
The findings are reported in the online journal Frontiers in Psychology.
The researchers set up an elaborate “market” in which the monkeys were trained to exchange tokens for rewards in form of chunks of flavoured ice, jelly, or juice.
They also learned that some rewards were cheap and others expensive in terms of how many one token could buy. A single token purchased three of the cheap goods, but only one of the pricier rewards.
The studies showed that while the monkeys understood differences in price, they stubbornly refused to fall for the idea that higher-priced rewards tasted better.
US lead researcher Laurie Santos, from Yale University, said: “We know that capuchin monkeys share a number of our own economic biases. Our previous work has shown that monkeys are loss-averse, irrational when it comes to dealing with risk, and even prone to rationalising their own decisions, just like humans. But this is one of the first domains we’ve tested in which monkeys show more rational behaviour than humans do.
“For humans, higher price tags often signal that other people like a particular good. Our richer social experiences with markets might be the very thing that leads us – and not monkeys – astray in this case.”