Abstract
Background There is concern that tongue protrusion may be maladaptive in individuals with Down syndrome (DS). However, tonguing and other self-manipulatory behaviours have been shown to contribute to emotion regulation in children without disabilities.
Method Sixty individuals with intellectual disability (40 with DS, 20 of mixed aetiology) and their parents were videotaped during a puzzle-book task. Empirical relationships between observed tongue protrusion, other observed nonverbal behaviours, and reported negative mood, maladaptive behaviours, and stress-inducing characteristics were assessed.
Results Individuals with DS and reported negative mood who did not engage in tonguing were more likely to display internalising and externalising behaviours and stress-inducing characteristics, whereas those who did engage in tonguing were not more likely to display these characteristics.
Conclusion These findings are consistent with the possibility that tongue protrusion serves an emotion regulation function for individuals with DS.