Long before children learn to speak they have already mastered complex concepts, some of which adults are slow to pick up on, a new study suggests. Language, the researchers say, may be merely a tool to help us express what we already know.
The relationship between language and thought is one of the most controversial questions in psychology. Some psychologists maintain that language largely precedes thought, and that a person's spoken tongue influences how he or she thinks about the world. Others contend that everyone starts out with a specific set of concepts, which are not influenced by one's native language.
By studying the ability of 5-month-old babies to distinguish among types of physical contact, psychologists Susan Hespos of Vanderbilt University and Elizabeth Spelke of Harvard University found that children reason before they rhyme. The researchers took advantage of a linguistic difference between Korean and English: Unlike English speakers, Korean speakers use different words to describe objects that fit tightly together, such as a ring on a finger, versus objects that fit loosely, like a hula hoop around a waist. Hespos and Spelke showed infants repeated examples of a cylinder being either tightly or loosely fitted into a hollow container until the babies became bored. When infants who saw the tight association were then shown the loose association (or vice versa), they regained interest, indicating that they distinguished between the two categories. Korean-speaking adults also recognized that a tight-loose connection was being demonstrated when shown the same objects, while their English-speaking counterparts were less clear about the nature of the display.
The findings, reported in the 22 July issue of Nature, suggest that all babies are born with the ability to recognize complex relationships, Hespos says. But as they grow up, children place less importance on concepts that aren't emphasized in their language.
"This work provides really nice evidence that thought precedes language," says Paul Bloom, a professor of psychology at Yale University. He believes that early recognition of certain concepts helps infants get a handle on the physical and social world. At the very least, he says, we now have a much clearer picture of how the infant brain works. "This work tells us [something about] what children know about the world before their first birthday."