Rats feel regret, experiment finds

With only an hour to eat, a diner hurries into his favorite restaurant. Deterred by a modest wait, he leaves, only to be burned by an even longer wait at the next restaurant. He immediately regrets his decision. This may seem like a typical “woulda, coulda, shoulda” situation — except in this case, the diner is a rat.

In laboratory tests, rodents exhibit regret, scientists report June 8 in Nature Neuroscience. After forgoing a good meal for a bad one, rats pause, glance back at what could have been and change their subsequent behavior. Scientists even caught signs of regret in rats’ brains: Nerve cells behaved as though the rats were back at the scene of the missed opportunity.

This study and other recent research are turning up hints of seemingly sophisticated behaviors in rodents which were previously thought to be exclusive to people, says neuroscientist Inbal Ben-Ami Bartal