SLPCohortAutism research : official journal of the International Society for Autism Research2026

Mismatching Expressions: Spatiotemporal and Kinematic Differences in Autistic and Non-Autistic Facial Expressions.

Connor T Keating, Sophie Sowden-Carvalho, Holly O Donoghue and 1 others

PMID 41548888

WHAT IT FOUND

Autistic adults posed facial expressions differently than non-autistic peers, relying more on mouth movements and less on eyebrows.

Alexithymia, not autism, predicted poor differentiation between angry and happy expressions. For non-autistic people, consistent self-expression aided emotion recognition; for autistic people, IQ did.

Key findings

01Autistic participants showed lower activation of brow muscles and higher activation of mouth muscles when posing anger and happiness compared to non-autistic peers.

02Alexithymia, rather than autism, was associated with less differentiated angry and happy facial expressions, meaning individuals with high alexithymia traits produced more overlapping emotional signals.

03The precision of a person's own spoken facial expressions predicted their ability to recognize emotions in others for non-autistic individuals, but this link was absent in autistic individuals, where IQ was the primary predictor.

STILL TO COME

How it was doneWhat they foundWhat it means for SLPs

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What it does not show

The study examined only posed, voluntary expressions, which may differ significantly from spontaneous, naturalistic emotional displays. The sample size was relatively small (51 participants), which may not capture the full heterogeneity of facial expression styles within the autistic population. Only three emotions (anger, happiness, sadness) were tested, limiting generalizability to other emotions like fear or disgust. The link between production and perception was correlational, so causality cannot be established.

Declared interests

The study was funded by the Medical Research Council (UK) and the European Union's Horizon 2020 programme. The authors declared no conflicts of interest.

The easy way to misread this

Do not assume that autistic individuals' facial expressions are 'less genuine' or 'atypical' in a pathological sense. The differences found were in muscle configuration (e.g., less eye squint in smiles), not necessarily in emotional authenticity. Also, do not attribute poor differentiation of angry and happy expressions solely to autism; this study found that alexithymia traits were the significant predictor.

Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →