The Influence of Social Word Features on Early Word Learning in Autistic and Non-Autistic Children.

Early word learning is a critical milestone for children, yet autistic children often experience delays in language development. Social communication differences are a core feature of autism and may contribute to variability in learning experiences. Prior research has shown that word-level features such as iconicity, concreteness, and input frequency shape the timing of word learning, but less is known about the role of social word features. This study examined whether social word ratings predict when words tend to be acquired by autistic and non-autistic children. Social word ratings were examined as a predictor of word-level autistic and non-autistic acquisition normative data, while accounting for word input frequency. Regression analyses demonstrated that social ratings significantly predicted vocabulary acquisition, even after controlling for word frequency. Additional analyses demonstrated that socialness ratings continued to be a unique predictor of word acquisition when other affective features of words were included in the model (i.e., arousal and valence); this was also the case when iconicity and concreteness were included. Importantly, differences in group and interactions with social ratings and group were not statistically significant in any of the models. Lastly, the pattern of highly social words being acquired later in vocabulary development was strongest for nouns; the association was non-significant when examining verbs separately. Thus, in addition to previously studied word features like concreteness, imageability, and iconicity, social word features are predictive of vocabulary acquisition. These findings highlight an overlap in word features that influence learning in autistic and non-autistic children.