Rats feel regret, study reveals

Rats are able to feel regret over their actions, a study has found, which makes it the first time the feeling has been identified in a mammal species that is not human.

The study conducted by Professor David Redish and his team from the University of Minnesota in the US, found that the rats showed regret after making the wrong decision.

According to the BBC, Professor Redish created a situation where rats where given a choice over waiting for a food reward for a set amount of time, or move onto another one.

Those who chose to move on displayed regretful behaviour when they found the next reward was even worse then the first.

This is the first time that regret has been has been identified in mammal species that is not human, the study has also shown that regret isn’t unique to humans.

Professor Redish said it was important to differentiate regret from disappointment.

"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," he told the BBC

The situation the researchers created allowed the rats to decide for themselves how long they were willing to wait for different foods.

Professor Redish equated the experiment to waiting in line at a Chinese restaurant and then giving up and going to the Indian restaurant close by, but still craving or wanting the Chinese food.

When the rats moved on from the good option and when offered bad the option, the researchers identified this as regret-inducing situation.

They found that the rats would pause and look back at the option they had passed up.

The rats also changed the decisions as they were offered more options after experiencing regret, they waited before they rushed to the next offering in another zone.

When rats were given the bad option without making the wrong decisions, they did not display any behaviour they did when they had rushed forward without waiting.