Does the brain create the mind? Many neuroscientists would say yes, but most of us—suggests University of Bristol neuroscientist Bruce Hood—carry a conviction that the mind is a special entity, distinct from our physical body. In other words, if it were possible to make an exact copy of someone's body, including the brain, most people's gut feeling is that the duplicate's consciousness would differ in some way from the original. Hood, with colleagues at Bristol and at Yale University, decided to investigate this question with young children to see whether we hold views on this subject early in life.

The researchers introduced five- and six-year-old kids to a hamster. The hamster had special physical traits—a broken tooth, for example—and each child interacted with the hamster to create a few memories. Then the investigators placed the animal in an elaborate box they call the duplicator and revealed a second, seemingly identical hamster. The children were asked a series of questions to reveal the degree to which they believed this new hamster was like the original.

Most children believed that physical traits, such as the broken tooth, were the same in both hamsters. About half of them, however, believed that the hamsters would not share memories. The findings, reported in the journal Cognition last December, suggest that we may develop our beliefs about the uniqueness of identity and mind at a very young age. The distinction between mental and physical replication was even greater when the original hamster was introduced with a name, “Dax.” In this case, about 70 percent of the children doubted that mental traits had duplicated along with physical ones. What's in the name? Hood suspects that naming primes kids to see the hamster as more human and unique.