Why Did the Monkey Steal?

There’s a crime wave at London Zoo. We’ve blogged in the past about monkeys that can do amazing things: use money, be rational actors, even learn grammar. Add to that list baby Bolivian monkeys who have taken to stealing sunglasses from visitors. But, say their keepers, the monkeys’ motives have nothing to do profit-maximizing. Here’s a hint: they’re so vain.