Brown rats at Karbu Mata temple, known as the Temple of Rats © Owen Lin / Barcroft Images / Barcroft Media via Getty Images
Studying emotion in any species is tricky. However, by observing changes in brain activity, cognitive processes and behaviour, scientists have clear indications that rats experience fear, excitement, pleasure, contentment, boredom and annoyance, as well as wants and desires. And now we can add regret to the list.
Work by David Redish of the University of Minnesota involved a gentle food-reward experiment that allowed rats to make their own decisions – and their own mistakes. The rats recognised when they made a bad decision, trying to correct it the next time.
Though the test doesn’t reveal the rats’ specific feelings, Redish has a theory: “I suspect rat regret might be tinged with the unhappiness of human regret, in that mild ‘Rats, I screwed up’ way.”