John Tierney in The New York Times:
If you own a dog, especially a dog that has anointed your favorite rug, you know that an animal is capable of apologizing. He can whimper and slouch and tuck his tail and look positively mortified — “I don’t know what possessed me.” But is he really feeling sorry? Could any animal feel true pangs of regret? Scientists once scorned this notion as silly anthropomorphism, and I used to side with the skeptics who dismissed these displays of contrition as variations of crocodile tears. Animals seemed too in-the-moment, too busy chasing the next meal, to indulge in much self-recrimination. If old animals had a song, it would be “My Way.”
Yet as new reports keep appearing — moping coyotes, rueful monkeys, tigers that cover their eyes in remorse, chimpanzees that second-guess their choices — the more I wonder if animals do indulge in a little paw-wringing. Your dog may not share Hamlet’s dithering melancholia, but he might have something in common with Woody Allen. The latest data comes from brain scans of monkeys trying to win a large prize of juice by guessing where it was hidden. When the monkeys picked wrongly and were shown the location of the prize, the neurons in their brain clearly registered what might have been, according to the Duke University neurobiologists who recently reported the experiment in Science.