A two-year-old can quickly link an object--whether a flashy rattle or a boring latch--to a word. Even a one-year-old can follow a parent's gaze to an object and match it with a word being spoken. But although anecdotal evidence seems to show that babies younger than one year can learn words, it remains unclear whether they are in fact mastering language. Now a new study reveals that 10-month-old infants can link words and objects, but only if the object is already interesting to them.

Psychologist Kathy Hirsh-Pasek of Temple University and her colleagues tested 44 infants for the ability to learn words. The infants averaged an understanding of nearly 14 words already, according to their mothers. But the researchers paired four novel objects--a blue sparkle wand and a white cabinet latch, a pink party clacker and a beige bottle opener--with four nonsensical words--modi, glorp, dawnoo and blicket--to test their ability to associate new words with new objects.

Sitting on their mothers' laps, the infants were exposed to the objects. First, they were allowed to play with an interesting and boring object pair followed by seeing the two objects placed on a rotating board. This was done to assess which object was more interesting to the babies and, as expected, they preferred the brightly-colored, noisy ones.

Then the researchers placed the two objects on a table in front of the infant. If the baby was in one group, the experiment leader pointed to the interesting object and labeled it with one of the nonsense words. If the baby was a member of the other group, the researcher pointed to the boring object and labeled it with the same nonsense word. Regardless of the researchers efforts, the infants looked at the object they found interesting.

But subsequent tests showed that the babies were also learning to associate it with the nonsense word. For example, when exposed to a new nonsense word, the babies would look away from the interesting object and search for a new one. Then the researchers returned to the original word and, surprisingly, 80 percent of the infants returned to looking at the original object.

This marks the first time such young infants have been shown experimentally to associate a word--even a made-up one--with an object, but, in contrast with their older peers, only one that they found interesting. "Ten-month-olds simply 'glue' a label onto the most interesting object they see," notes Shannon Pruden, a doctoral student and lead author of the study to appear in the journal Child Development. "Perhaps this is why children learn words faster when parents look at and name objects the infants already find interesting."

This inability to link social cues, words and objects may also explain why early word learning is so slow but accelerates rapidly around the age of 18 months. "The 18-month-old is a social sophisticate who can tap into the speaker's mind and the vast mental dictionary that the adult has to offer," adds Hirsh-Pasek. "At 10 months, they just cannot take the speaker's perspective into consideration."