This is from the DSM-V: "Deficits in social-emotional reciprocity..." ...so maybe it's not that they completely lack empathy but rather process it in a way that we don't recognize and therefor categorize as a deficit?
Yes, while empathy is not specifically mentioned, it is my understanding that it is referred to in that excerpt of DSM-5, thereby explaining the assessment of empathy as a part of the ADOS.
I may be wrong, but I believe the assessed symptomology for empathy is deficit in
demonstrated empathy (an observable characteristic, what one sees from the outside), not in one's self-reported experience of empathy (what one feels on the inside).
