Reduced contagious yawning in psychiatric disorders: a systematic review of potential social-cognitive mechanisms.

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TL;DR: A systematic review of 23 studies found that contagious yawning is reduced in autism spectrum disorder, psychopathic traits, and schizophrenia-spectrum disorders, but the underlying reasons differ by condition and the evidence is limited by small samples and methodological variation.

What the Study Found

Contagious yawning, the tendency to yawn after seeing or hearing someone else yawn, has long been studied as a window into social cognition. Researchers have proposed that it reflects empathy, emotional contagion, self-processing, Theory of Mind (ToM), and action observation mechanisms such as the human mirror neuron system (hMNS). This systematic review, published in *Frontiers in Psychiatry*, set out to test whether reduced contagious yawning appears across psychiatric conditions and what mechanisms might explain it.

The authors searched PubMed, PsycINFO, and Scopus, screened studies against predefined criteria, and assessed risk of bias using Joanna Briggs Institute (JBI) critical appraisal tools. Twenty-three studies met inclusion criteria. Reduced contagious yawning was reported in autism spectrum disorder (ASD), psychopathic traits, and schizophrenia-spectrum disorders, though the strength of findings varied considerably across these groups.

In ASD, reduced contagious yawning was associated with differences in social attention and gaze allocation, with some studies pointing to oxytocin-related processes and broader social-cognitive differences. The review does not establish that these factors are causal. They are associations reported across studies with varying designs.

In psychopathic traits, the evidence more consistently pointed to affective-interpersonal features and reduced emotional responsiveness as correlates of lower contagious yawning. This is one of the more coherent patterns in the review, though the number of studies remains modest.

Evidence for schizophrenia-spectrum disorders was the most limited. Proposed explanations included impairments in social cognition, ToM, and negative symptoms, along with the possibility of medication effects. The authors explicitly note that these mechanisms remain speculative given the available data.

Neuroimaging and electrophysiological studies implicated brain systems involved in social cognition, self-processing, and action observation. However, the authors conclude that the specific role of the hMNS remains uncertain. This matters because the mirror neuron explanation has been widely cited in popular accounts of yawning. The review suggests that contagious yawning likely reflects altered social-cognitive processing more broadly rather than empathy alone.

The authors also emphasize important limitations. Sample sizes were small, study designs varied, and the operational definition of contagious yawning differed across studies. These factors make it difficult to draw firm conclusions about clinical significance or to use contagious yawning as a diagnostic marker. [E tier, as a diagnostic use is not supported]

What This Means for You

This review is primarily a research synthesis, not a set of recommendations. A few points are worth keeping in mind:

No supplement or habit is supported by this study as a means to alter contagious yawning or related social-cognitive outcomes.

Study Details

Sources

1. Systematic review: *Reduced contagious yawning in psychiatric disorders: a systematic review of potential social-cognitive mechanisms.* Frontiers in Psychiatry. PubMed. https://pubmed.ncbi.nlm.nih.gov/42898448/

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