I keep reading about this sort of situation: the person showed no sign of any difficulty in conversation in a half hour interview - that could be a GP barring access to diagnosis, an employer assessing a job candidate, the PIP assessors etc etc.
The assumption seems to be that autism is a disability in speaking, or that people on the spectrum cannot converse with others.
It is frustrating that this difficulty amongst health professionals, social workers, educators, employers (and DWP staff!!) runs on and on, without any improvement in understanding.
Part of the problem seems to be whether people on the spectrum engage in collective human behaviour, in part what I think the Sheffield academic Digby Tantam means by the "interbrain". There seem to be two things happening. People on the spectrum cannot pick up on collective responses, and cannot distinguish spoken information for the benefit of assembled persons of which assembly they are one.
Collective responses depend on non-verbal communication (I've heard supposedly scientifically educated professionals assert they don't believe in all that body language nonsense). No-one seems to think facial expression and body language are that important, but I think it is significant that people on the autistic spectrum have trouble registering it. They cannot read such information properly, and they cannot generate it properly.
When texting in any medium where communication is the written word seen rather than the spoken word heard, people use emoticons (smilies) to qualify whether what they are saying is serious or funny, happy or sad. That implies to me that this information is conveyed in spoken socialisation by means other than just words. People on the spectrum seem to have difficulty with these "real world" emoticons.
Many people on the spectrum cannot filter out background noise properly. Therefore they have difficulty distinguishing spoken messages meant for everyone around them to hear. They often need someone to speak to them directly. This is often reported about schoolchildren in classrooms, the autistic child doesn't pick up on an instruction to the whole class.
It isn't just about how the teacher enunciates this, or calls attention, by raising his/her voice, or a hand gesture. It is about how the class collectively responds. They all recognise the instant need to pay attention. If someone isn't paying attention they get nudged or shhhh'd at. The person on the autistic spectrum often misses this completely. That might be because they are too pre-occupied with their own thoughts. I think it is more likely they are having to work much harder to follow what is going on around them to sift out relevant sounds, or observe any relevant actions, that they are not relaxed enough to be receptive to the "interbrain" - or they just aren't connected to the interbrain to start with.
Something that often happens to me in a social situation might represent this - I often find myself suddenly aware that everyone around me is having a drink, I haven't got one. If I ask I invariably get told I was asked if I wanted a drink and I didn't respond.
When I look into this further I find that usually this amounted to raised imaginary glass, or raised imaginary tilted bottle gestures. I can understand what the gestures mean. I could conciously look out for them if I wasn't overwhelmed with other things already. But it is clear that everyone else picks up on these signals with great ease, even instinctively. I don't. I haven't any awareness of them at all.
As I understand it, according to recent figures, 90% of research funding goes on finding the cause of autism or cures, 6% goes on improving diagnosis, and some miniscule fraction of the remaining 4 percent goes on trying to improve the lives of those living with autism. So it is hardly surprising there has been zero progress in understanding social interaction.
The sad reality is that those professionals with all their preciousness, pomp and hippocratic oaths really don't care a button for people with autism. Otherwise they might show greater endeavour to understand what it is makes social interaction difficult for people on the spectrum.
In the meantime we are stuck with platitudes - <well he seemed to carry on a perfectly normal conversation in a half hour interview, so I cannot really be bothered to try to find out what else is causing this autistic person to experience difficulty>.