Topic choice, topic synchrony, and utterance function during mother–child play
sessions at age 3 were examined in 32 late talkers (identified at 24 to 31 months) and 21
comparison children, matched at intake on age, SES, and nonverbal ability. At age 3, late talkers
had significantly lower MLUs and IPSyn scores than comparison children. Late talkers and
comparison children did not differ in number of utterances, topic initiation, topic synchrony, use
of commands, reactions to commands, or conversational fillers. However, late talkers asked
significantly fewer questions, provided fewer answers to maternal questions, made fewer
declarative statements, and were less likely to elaborate on their own topic than comparison
children. Mothers of late talkers produced significantly more utterances and asked many more
questions, but otherwise they did not differ from mothers of comparison children. In both groups,
children and mothers were highly synchronous. When late talkers were divided into two groups
(children with continuing delay vs. “late bloomers” who were within the normal
range in MLU), the subgroups did not differ significantly from each other on any conversational
measure.