Facial feedback mechanisms in autistic spectrum disorders.

The team ran three lab tests with 48 autistic teens. They asked each teen to hold a pen three ways: between teeth to make a smile, between lips to make a frown, or in the hand.

Right after each pose they rated cartoon faces for funniness. Same setup was run with 48 typical teens for comparison.

Typical teens felt happier after smiling and sadder after frowning. Autistic teens gave the same ratings no matter how they held the pen.

Their emotions did not budge even though their faces copied the poses perfectly.

Stagg et al. (2022) extend the picture. They showed autistic teens can name emotions on still photos, but miss when someone fakes a smile in real life. Together the studies say: face reading is partly intact, face feeling is not.

Spriggs et al. (2015) and Hartston et al. (2023) trace the roots back further. Babies later diagnosed with ASD stop looking at eyes after nine months. Adults with ASD keep weak inner face templates. The broken facial feedback loop seen here sits in the middle of that timeline.

Kamio et al. (2006) and Muth et al. (2014) match the null result with different tasks. Autistic kids show no gut reaction to happy faces and do not follow gaze after eye contact. The pattern is stable: faces send social signals that do not land.

Do not count on smiley-face tricks to lift mood in clients with ASD. If you want to teach emotion, use clear words, pictures, or video models instead of asking them to move their own face and wait for a feeling.