Psychologist logo
Capuchin monkey on a tree
Cognition and perception, Developmental

Cognitive dissonance observed in children and monkeys

Remarkably, psychologists at Yale University have now shown that young children and monkeys engage in these sorts of thought processes too.

24 October 2007

By Christian Jarrett

Roast beef or chicken for dinner? Spain or Greece for a holiday? If we believe two or more options are equally appealing, yet we have to plump for just one choice, it can cause us psychological discomfort – what psychologists call 'cognitive dissonance'.

Having made a decision, say, for chicken or Greece, what people often do to alleviate this dissonance, is update their attitudes to match the choice they made – the beef would have been too rare, Spain would have been too hot. Remarkably, psychologists at Yale University have now shown that young children and monkeys engage in these sorts of thought processes too.

Forty 4-year-olds used a scale of smiley faces to indicate how much they liked a range of animal stickers. For each child, the researchers identified three stickers which that child liked equally – let's call these A, B, C. Each child then faced two choices – first to choose which of A or B they would like to take home. Afterwards, they then had to choose between sticker C and whichever sticker (A or B) they hadn't selected before.

In the latter case, if the children liked the stickers equally, then on average they should have opted for sticker C over either A or B 50 per cent of the time, but in fact sticker C was selected in 63 per cent of such choices. The reason, the researchers say, is because, to reduce cognitive dissonance, the children had downplayed the appeal of whichever sticker (A or B) they had chosen not to pick earlier, thus tipping the balance in favour of C.

Moreover, the same pattern was found in an almost identical experiment with six capuchin monkeys who chose between different coloured, equally appealing M&M sweets. After a given colour was rejected, its future appeal suffered as the monkeys appeared to update their attitudes to match their earlier choices.

"Our findings hint that some of the mechanisms that drive cognitive-dissonance-reduction processes in human adults may emerge as a result of developmentally and evolutionarily constrained systems that are consistent across cultures, ages, and even species," Louisa Egan and colleagues concluded.

Further reading

Egan, L.C., Santos, L.R. & Bloom, P. (2007). The origins of cognitive dissonance. Evidence from children and monkeys. Psychological Science, 18, 978-983.