University of Pennsylvania psychologists have overturned the dominant theory of how children learn their first words, suggesting that it occurs more in moments of insight than gradually through repeated exposure.
The research was conducted by postdoctoral fellow Tamara Nicol Medina and professors John Trueswell and Lila Gleitman all of the Department of Psychology in Penn's School of Arts and Sciences and Jesse Snedeker, a professor at Harvard University.
The current, long-standing theory suggests that children learn their first words through a series of associations; they associate words they hear with multiple possible referents in their immediate environment.
"This sounds very plausible until you see what the real world is like.It turns out it's probably impossible," said Gleitman.
To demonstrate this, the Penn team conducted three related experiments, all involving short video segments of parents interacting with their children.
Subjects, both adults and preschool-aged children, watched these videos with the sound muted except for when the parent said a particular word which subjects were asked to guess; the target word was replaced with a beep in the first experiment and a nonsense placeholder word in the second and third.
By asking the subjects to guess the target word after each vignette, the research could get a sense of whether their understanding was cumulative or occurred in a "eureka" moment.
The evidence pointed strongly to the latter. Repeated exposure to the target word did not lead to improved accuracy over time, suggesting that previous associations hypotheses were not coming into play.
Moreover, it was only when subjects saw an HI vignette first did the accuracy of their final guesses improve; early HI vignettes provided subjects with the best opportunity to learn the correct word, and most guessed correctly when presented with them.
"It's as though you know when there is good evidence, you make something like an insightful conjecture," said Gleitman.
The study was published in the journal Proceedings of the National Academy of Sciences last week.