In a study that could shed light on how infants first grasp the concept of number–as well as the evolutionary origins of that ability–researchers have found evidence that babies have an abstract numerical sense even before they learn to talk.
Duke University scientists Kerry Jordan and Elizabeth Brannon published their findings the week of Feb. 13-17, 2006, in the Proceedings of the National Academy of Sciences.
The research was sponsored by the National Institute of Mental Health, the National Science Foundation and the John Merck Fund.
Jordan and Brannon presented seven-month-old infants with the voices of two or three women saying, “Look.” At the same time, they showed the babies two video images: one with two women saying the word and the other with three women doing so. The researchers found that the babies spent significantly more time looking at the video image that matched the number of women talking. From that, the researchers concluded that the infants were transferring their perception of number across two different senses, sight and sound–which suggested, in turn, that babies have a truly abstract sense of numerical concepts.
In earlier work, Jordan and Brannon performed similar tests on monkeys, which also seem to exhibit numerical perception across senses.
“As a result of our experiments, we conclude that the babies are showing an internal representation of ‘two-ness’ or ‘three-ness’ that is separate from sensory modalities and, thus, reflects an abstract internal process,” said Brannon. “These results support the idea that there is a shared system between preverbal infants and nonverbal animals for representing numbers.”
From National Science Foundation