Boston University psychologist Patricia Ganea and her colleagues asked 19-month and 22-month -old infants to name a toy that was presented to them in the lab. After a short time, they took the toy from the infants, and placed it in an adjoining room.
While the toy was out of view, lab assistants told the infants that the toy had become soaking wet after someone mistakenly spilled a bucket of water.
The researchers wanted to determine whether the infants would incorporate the information told to them into their mental representation.
It could be done by testing whether the kids would reach for the newly wet stuffed toy or a dry version identical to what they had been previously presented, upon being asked to retrieve the animal from the next room.
The researchers found that the 22-month-olds, but not the 19-month-olds, were able to identify the toy based solely on the property that they were told about but had never seen.
The finding indicates that before the end of their second year, infants had become capable of updating their knowledge using what other people told them.
"This nascent ability constitutes a significant cognitive advance, enabling children to vastly expand their knowledge by learning about the world through verbal interaction," says Ganea.
The study has been published in Psychological Science, a journal of the Association for Psychological Science.