It’s not just me, monkeys have regrets too

Posted on May 27, 2011


Last night I went to bed without uttering a word to The Northerner, a combination of being very grumpy and very tipsy after a lot of wine and a really stressful day at work – not my most attractive qualities.

This morning my little black cloud has lifted and he was brave enough to suggest that perhaps I was being over sensitive. And he’s right, I do regret throwing my toys out of the pram like a petulant child.

new research says monkeys feel regret like humans

Much like me, a new study has found that monkeys show regret and wonder what might have been. Obviously they’re not tanked up on a potent liquid dinner when they go through this.

According to researchers at Yale not only are these findings very interesting but they could also shed some light on some of the most basic human psychological traits.

The general belief is that animals learn on their previous experiences, usually on a trial and error basis. But Daeyeol Lee, a professor of neurobiology at the Yale School of Medicine and co-author of the study said for a long time he believed this theory was inaccurate, and has set about proving his hunch.

He said: “When people have regret, they’re thinking about what could have happened; it’s about imagining what could have happened,” he said.

“The reason you do this is because it actually broadens the potential for learning tremendously. It seems like such a fundamental question that I would be surprised if it were exclusive to humans.”

The authors say that regret happens in two different forms, both of which take place in parts of the prefrontal cortex of the brain. Most regret is good, because it helps you learn and evolve; but when people obsess about their regrets, this is dangerous and can often lead to depression.

In order to test their theory researchers taught Rhesus macaques (Macaca mulatta) a familiar childhood game of ‘scissor, paper, stone’. The monkeys weren’t taught to sign in order to play the game, that would have been impressive. They were given a computer simulation of the game and researchers monitored their brain’s activity while playing.

Scissor, Paper, Stone

If the monkeys won, they would get a large reward, if they tied, a small reward, and they got nothing when they lost.

If a monkey lost a game –  by, for example picking stone when the winning move would have been paper – then it became much more likely to choose the previous winning object, ie: paper in the next round.

The practical side of regret – where people learn from it – triggers the dorsolateral prefrontal cortex.

However, in the second set of findings, the animals’ neuronal activity in these situations revealed they were experiencing both rational and emotional forms of regret triggering the orbitofrontal cortex.

In other words, Professor Lee said, they were able to think abstractly and imagine an alternative outcome.

He said: “Your brain is running this mental simulation about how you could do things differently in the future to get a better outcome. It’s an important first step. If someone has a pathological amount of regret, and you want to ameliorate it some way, you can target those areas. And when you’re testing those drugs, then you know where to look.”

It is hoped this research may be able to help treat obsessive behaviour in mental health patients. The study is published in the Neuron Journal.