In the baby research, published in 2002, scientists had 3-to-12-month olds watch as a woman did a strange thing: she turned on a light by tapping the top of a box with her forehead. Sometimes when she took this odd approach her hands were in their normal place by her sides. During other runs, she was wrapped in a blanket so snugly that her arms and hands were pinned. Once the babies had seen what the woman did, it was their turn. How would they turn on the light?
If they saw her use her forehead when her hands were wrapped in the blanket, they seemed to infer that she did this only because the more efficient strategy–using the hands–was not possible. As a result, when it was their turn, the babies used their hands to turn on the light. But if the woman used her forehead when her hands were perfectly usable, the babies did, too: they had apparently concluded that if she used this weird tactic despite having use of her hands, then there must be something to it. The babies were imitating selectively.
Apes do this also, and scientists at the University of Vienna wondered how far down the tree of life the behavior originated. They gathered up 54 dogs and divided them into three groups. As one group looked on, a specially-trained border collie got food by pressing a bar with its paws, instead of using the easier (for dogs) tactic of grabbing the bar with its mouth. Given a chance to depress the bar to get food, 83 percent of these dogs used their paws: like the babies, they apparently inferred that if the collie was using its paws even when its mouth was perfectly available, there must be a doggone good reason for it. The second group of dogs watched the collie press the bar with its paws, but in this case the collie had a ball in its mouth (analogous to the woman wrapped in a blanket). When it was their turn, only 21 percent of the dogs who saw this used their paws; they had concluded, it seems, that while it might make sense to use your paws if your mouth is out of commission, under ordinary circumstances you should use your mouth. Of the dogs who witnessed no demo of any kind, but were simply left to their own devices about how to depress the bar, only 15 percent used their paws, the Austrian scientists reported in the online edition of Current Biology. The dogs copy a behavior only if it seems to make sense.
Other researchers told ScienceNOW, the daily news site of the journal Science, that this is the first good evidence of selective imitation in dogs. But one question remains: did dogs evolve this independently millions of years ago, or only once they became domesticated and learned from humans that some things are worth copying and some are not?
