‘Has anybody seen the, uh, child genius around here?’

 Children use uh and um to help them acquire language.  

A young child’s world is full of obstacles that they need to negotiate, not least in language.  Imagine constantly listening to lots of gobbledegook and having to work out what the speaker is talking about.  There may be some words you recognise, or even lots, depending on your age, but there are many others that you don’t.  A child will use many different clues to help them understand what the speaker is referring to, including watching to see where a speaker is looking or where they are pointing, and checking to see what objects are in the vicinity to work out if any of them are what is being referred to.

Celeste Kidd, Katherine White and Richard Aslin believe that children call on an additional resource..  They investigated what children infer from speech ‘disfluencies’, which are the uh and um sounds speakers use to fill pauses in speech.  

These often occur before unfamiliar or infrequent words, often those that have not been mentioned before in the conversation, as in this example:

CHILD:                     Telephone?

MOTHER:                  No, that wasn’t the telephone, honey. 

                              That was the, uh, timer.

Here the mother fills a pause with uh as she has difficulty trying to remember an infrequently used word that is, in addition, a new topic in this conversation with her child. 

The researchers decided to find out just how far children used these speech disfluencies to predict that  a new, unfamiliar word was about to occur in conversation.  They did this by ‘eye-tracking’ the children to see where they looked when they were shown pictures of two objects on a screen, one familiar such as a ball and one unfamiliar, totally made up object with an invented name[1].  They showed the children both objects whilst they listened to three different phrases. Firstly, they heard I see the ball, next ooh what a nice ball and lastly, either look at the ball/wug or look at the, uh, ball/wug! Each time they watched to see where the child’s eyes looked in the moment before they heard the name of the object.  This experiment was conducted on three different age-groups of children spanning from 16 months to 2 ½ years old.

Their results show that children do indeed use the speech disfluencies uh and um to predict that a new or unfamiliar word is about to be heard for a new or unfamiliar object.  The children consistently looked at the unfamiliar object when the word referring to the object was preceded by uh and um, even when it was in fact a familiar object that was subsequently named, suggesting that they were anticipating hearing a word they were unfamiliar with.  Even more interestingly, this ability seems to be learned through experience as the incidence of it happening increased with the age of the child.  So, children may be subconsciously learning that often disfluencies in speech (like uh and um) signal that the speaker is having difficulties and they therefore look for the object that is causing the difficulties, usually an object that seems new and different.

This is a fascinating discovery and one that again proves the sophisticated and astoundingly intelligent way that children learn and use language.   

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Kidd, Celeste, White, Katherine and Aslin, Richard (2011) Toddlers use speech disfluencies to predict speakers’ referential intentions. Developmental Science 14 (4): 925-934

DOI: 10.1111/j.1467-7687.2011.01049.x

This summary was written by Gemma Stoyle

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[1] For a list of these objects and the pictures that the children were shown visit http://babylab.bc.rochester.edu/stim/disfluency/.