Point, walk, talk: Links between three early milestones, from observation and parental report
Moore, Dailey, Garrison, Amatuni, Bergelson
Around
their first birthdays, infants begin to point, walk, and talk. These
abilities are appreciable both by researchers with strictly standardized
criteria and caregivers with more relaxed notions of what each of these
skills entails. Here, we compare the onsets of these skills and links among
them across two data collection methods: observation and parental report. We
examine pointing, walking, and talking in a sample of 44 infants studied
longitudinally from 6 to 18 months. In this sample, links between pointing
and vocabulary were tighter than those between walking and vocabulary,
supporting a unified sociocommunicative growth account. Indeed, across
several cross-sectional and longitudinal analyses, pointers had larger
vocabularies than their nonpointing peers. In contrast to previous work, this
did not hold for walkers’ versus crawlers’ vocabularies in our sample.
Comparing across data sources, we find that reported and observed estimates
of the growing vocabulary and of age of walk onset were closely correlated,
while agreement between parents and researchers on pointing onset and talking
onset was weaker. Taken together, these results support a developmental
account in which gesture and language are intertwined aspects of early
communication and symbolic thinking, whereas the shift from crawling to
walking appears indistinct from age in its relation with language. We
conclude that pointing, walking, and talking are on similar timelines yet
distinct from one another, and discuss methodological and theoretical
implications in the context of early development.