Autistic adults display different verbal behavior only in mixed-neurotype interactions: Evidence from a referential communication task.

Recent research shows that in conversations, both participants influence the outcome. More specifically, conversations do not go as smoothly when autistic and non-autistic people talk together compared to when people of the same neurotype (either all autistic or all non-autistic) talk to each other. In studies finding a "same-neurotype communicative advantage", interaction partners knew about each other's neurotype. Because of this methodological choice, it is unclear whether mixed-neurotype interactions go less smoothly because participants knew they were interacting with a different neurotype or because each neurotype really has a distinct communication style. In our study, 134 adults were grouped into same-sex pairs: 23 autistic, 23 non-autistic, and 21 mixed-neurotype pairs. The pairs did not know if the other person was autistic or not. They completed an online task where the "Director" instructs the "Matcher" to reorder abstract pictures. Pairs did this task in two ways: by typing in a live chat and by speaking into a microphone without video. The study looked at how long the task took and how much the Director talked/wrote. Results showed that non-autistic pairs were faster to complete the task than autistic pairs and mixed pairs, meaning pairs with at least one autistic person were slower in general to complete the task. Interestingly, in mixed pairs, only autistic Directors produced more words than non-autistic Directors, in both typing and speaking. These findings suggest that even without knowing about their partner's neurotype and seeing/hearing their partner, autistic adults communicate differently when they interact with a non-autistic person.