New study reveals autistic and non-autistic people use different facial ‘emotional languages’

Facial expressions are often treated as a universal emotional code, but new research suggests that is not entirely true. A large-scale study has found that autistic and non-autistic adults tend to show basic emotions on their faces in systematically different ways, which may fuel mutual misunderstandings in everyday social interactions.

The findings, based on highly detailed tracking of facial movements, suggest that autistic people are not less emotional, but may be using a different “emotional language” through their expressions.

How the study was designed

The research was carried out at the University of Birmingham and published in the journal Autism Research. The team recruited 25 autistic adults and 26 non-autistic adults, who together produced nearly 5,000 facial expressions during the experiment.

Participants were asked to display three core emotions: anger, happiness and sadness. They did this in two contexts: first by matching their facial movements to specific sounds, and then while speaking. Throughout the tasks, advanced facial motion tracking captured minute changes in facial muscles.

In total, the system recorded more than 265 million data points, creating one of the most detailed databases of emotional facial movements assembled so far.

Distinct facial patterns in autism

When the researchers compared the expressions, clear group differences emerged. Autistic participants showed a broader variety of facial configurations overall, and characteristic patterns appeared for each emotion:

• Anger: Autistic adults relied more on movements around the mouth, while using their eyebrows less than non-autistic adults.
• Happiness: Smiles tended to be more subtle and were less likely to involve the eyes, resulting in expressions that did not fully “reach the eyes.”
• Sadness: Autistic participants often produced a downturned expression by lifting the upper lip more than non-autistic participants.

According to the lead author, Dr. Connor Keating, now at the Department of Experimental Psychology at the University of Oxford, the differences concern not only which muscles move, but also how fluidly expressions take shape over time. This combination of distinct appearance and timing may make it harder for each group to correctly read the other’s emotional state.

Alexithymia and more ambiguous expressions

The team also looked at alexithymia, a trait that involves difficulty recognizing and describing one’s own emotions. Alexithymia is relatively common among autistic people, but also occurs in the wider population.

Regardless of autism diagnosis, participants with higher levels of alexithymia tended to show less clearly defined facial expressions of anger and happiness. These expressions appeared more ambiguous, potentially making it harder for others to interpret what the person was feeling.

This suggests that both autism and alexithymia can shape how emotions are shown on the face, and that these influences may overlap in complex ways.

Why emotional misunderstandings occur

The findings provide a possible explanation for long-standing reports that autistic people often struggle to recognize the emotions of non-autistic people, and that non-autistic observers can misread autistic expressions.

Dr. Keating notes that the study points to a mutual mismatch rather than a one-sided issue. If two people are using slightly different facial “dialects” for the same emotions, even intense feelings can be easily misinterpreted.

This perspective challenges the assumption that autistic people inherently lack emotional expression. Instead, it suggests that their emotional signals may simply follow a different pattern that non-autistic observers are not used to decoding.

Different, not deficient

Senior author Professor Jennifer Cook from the University of Birmingham emphasizes that these differences should not automatically be seen as impairments. She argues that autistic and non-autistic expressions may both be valid and meaningful within their own social contexts, much like different spoken languages.

From this viewpoint, difficulties in emotional communication between autistic and non-autistic people are better understood as a two-way challenge. Both sides may need to learn more about each other’s expressive styles in order to improve mutual understanding.

The researchers are continuing to investigate how these differing emotional “languages” affect real-world interactions and whether training or awareness-raising could help bridge the gap.

Funding and future directions

The study was funded by the UK Medical Research Council (MRC) and the European Union’s Horizon 2020 Research and Innovation Programme.

By combining large-scale motion tracking with psychological assessment, the research opens the door to more precise mapping of how emotions are expressed and perceived across different neurotypes. In the long term, such work could inform more inclusive communication strategies in education, healthcare and everyday social life.