By Zoe Gough
Rats experience regret when their actions make them miss out on better food options, a study has found.
It is the first time regret has been identified in mammals other than humans.
Researchers created situations where rats had to choose whether to wait a set amount of time for a food reward, or move onto another one.
Those that moved on and found the next offering was even worse showed regretful behaviour.
The study was conducted by neuroscientists based at the University of Minnesota, US; their findings are reported in Nature Neuroscience.
It suggests thoughts similar to regret can affect the future decisions rodents make and dispels the belief that regret is unique to humans.
Prof David Redish, from the US-based research team, said it was important to differentiate regret from disappointment.
“Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off,” he said.
“The hard part was that we had to separate disappointment, which is just when things aren’t as good as you hoped. The key was letting the rats choose.”
They developed a task called Restaurant Row, in which rats decided how long they were willing to wait for different foods during a 60-minute run.
“It’s like waiting in line at the restaurant,” Prof Redish. “If the line is too long at the Chinese restaurant, then you give up and go to the Indian restaurant across the street.”