Exchange Every Day reports this morning:
Uhs" and "ums" that fill pauses when adults speak to toddlers, may actually aid the toddlers in expanding their vocabularies. In an article titled, "Toddlers use speech disfluencies to predict speakers' referential intentions," Celeste Kidd, Katherine S. White, and Richard N. Aslin at the University of Rochester (NY) found that such pauses often occur before adults use a word that is infrequent or unfamiliar in their speech or prior to using a word for the first time in a conversation.
In their research, reported in Developmental Science, Kidd found that when such a pause occurred, the toddlers paid significantly more attention to the unfamiliar for the next two seconds.
From the abstract:
We conducted an eye-tracking study to investigate whether young children can make use of this distributional information in order to predict a speaker’s intended referent. Our results reveal that young children (ages 2;4 to 2;8) reliably attend to speech disfluencies early in lexical development and are able to use disfluencies in online comprehension to infer speaker intent...