Children vary greatly in the number of words they know when they enter school, a major factor influencing subsequent school and workplace success. This variability is partially explained by the differential quantity of parental speech to preschoolers. However, the contexts in which young learners hear new words are also likely to vary in referential transparency; that is, in how clearly word meaning can be inferred from the immediate extralinguistic context, an aspect of input quality. To examine this aspect, we asked 218 adult participants to guess 50 parents' words from (muted) videos of their interactions with their 14- to 18-mo-old children. We found systematic differences in how easily individual parents' words could be identified purely from this socio-visual context. Differences in this kind of input quality correlated with the size of the children's vocabulary 3 y later, even after controlling for differences in input quantity. Although input quantity differed as a function of socioeconomic status, input quality (as here measured) did not, suggesting that the quality of nonverbal cues to word meaning that parents offer to their children is an individual matter, widely distributed across the population of parents.
This research output has an Altmetric Attention Score of 85. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 09 August 2026.
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Outputs from Proceedings of the National Academy of Sciences of the United States of America
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Outputs of similar age from Proceedings of the National Academy of Sciences of the United States of America
#106
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Altmetric has tracked 34,548,112 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 98th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 119,141 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 40.1. This one has done particularly well, scoring higher than 91% of its peers.
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We're also able to compare this research output to 1,000 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 89% of its contemporaries.
