Anne Young was on vacation visiting the Sacred Monkey Forest in Bali. "The pair had been together a few days, and whenever the park staff tried to capture the kitten, it would just run back to the monkey," Anne says. The macaque, a young male, would groom his feline friend, hug and nuzzle it, and even lay his head on the kitten’s head as if it were a pillow.I mention this because I think keeping pets is one of the millions of things we do that have no evolutionary purpose. Pet keeping is probably a stray product of the emotional machinery we developed to do other things. The emotional modules that encourage us to care for our babies, seek companionship, and play are sometimes co-opted into relationships with other animals, to our joy and their advantage.
(The relationship between wolves and human hunters began as something completely different, although of course it is now mostly emotional and may have had some of these elements from the beginning.)