Your canine may not be so different from your infant. A famous psychological experiment showed that infants will almost always look for an object in its initial hiding place even if they've seen it moved somewhere new. A recent experiment shows dogs make the same bizarre mistake.

In the experiment, published this week in Science, an adult talks to the infant or dog as they hide the object. After a few trials, the adult moves the object. Both subjects will continue to search for the object in the first location even though they've seen it hidden somewhere new. The vocal interactions are key, for if they are not present, both babies and dogs make fewer mistakes.

Intriguingly, human-reared wolves never make this mistake in experiments. That both dogs and infants make the same error, and wolves don't, led researchers to believe that 10,000 years of domestication has changed canine genetics. In some cases, dogs are more like humans than their four-legged cousins.

But how deep does the resemblance run? "We think the similarities between human infants and dogs in this test are only surface similarities," Dr. József Topál, a psychologist at the Hungarian Academy of Sciences and lead author of the paper, told Science.

Although both dogs and babies make the same mistake, more experiments showed each subject's motivations may be different. Unlike the first experiment, a second adult moved the object to its new hiding place. Infants continued to make the same error. But dogs did not; they looked in the new hiding place.

The dog's behavior can be interpreted as an urge to satisfy whichever human is in the room - perhaps yet another genetic imprint. The babies' behavior, however, can be interpreted as "learning," treating the instruction of all adults equally. What they learn, they generalize. The object is always hidden in location A no matter what their eyes tell them. This behavior may be unique to humans.

"It is possible that neither dogs nor any other nonhuman species communicate generalized...information in this way," write Drs. Michael Tomasello and Juliane Kaminski of the Max Plank Institute in a commentary in Science.

It seems a strange study group: infants and dogs. There is an intriguing connection between dogs and humans, for just as wolves do not understand spoken human commands, our great ape relatives also fail at the task. For whatever reason, the link is only between man and his best friend.