From DSM-2300:
https://www.fysh.org/~zefram/allism/allism_intro.txt
edit: "The underlying trait that makes people allistic is a dysfunction of the parts of the brain dealing with emotion. Allistic people lack the capacity to independently experience emotions. That is not to say they lack emotions: far from it, the allistic mind experiences emotions just like any other. The dysfunction is that the allistic person's emotional state is not determined by eir own thought processes but instead is borrowed from other people that are expressing emotion nearby. Emotional cues in tone of voice, posture, facial expression, and so on, cause the allistic person to automatically and unavoidably experience the same emotion being expressed."
https://bookshop.org/p/books/semiosis-sue-burke/7103931