There's a term for this - "flat affect" and I see it in a good portion of the aspies I know. I don't have flat affect now, but I had this at times as a kid. However, I seem to process other people's facial expressions naturally, so I get a little uneasy when I see flat affect. When I see other aspies displaying flat affect, I become confused sometimes because I have less of a sense of how they are really feeling about something. Most of the time, it's in a situation where they are truly enjoying themselves (and they have told me this afterwards) but they are not showing the level of enthusiasm usually expected...not just in their face, tone of voice, or in the things they are saying.
I think that if someone on the spectrum has flat affect, they are very likely to be misunderstood by people - i.e. others will ask you what is wrong because you look sad, even if you don't feel sad. Your facial expressions and your true emotions don't match, and this will confuse people. I think that if you have this, it's important to be aware of it so that you can explain to others what you are really feeling at a given time.
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Given a “tentative” diagnosis as a child as I needed services at school for what was later correctly discovered to be a major anxiety disorder.
This misdiagnosis caused me significant stress, which lessened upon finding out the truth about myself from my current and past long-term therapists - that I am an anxious and highly sensitive person but do not have an autism spectrum disorder.
My diagnoses - social anxiety disorder and obsessive-compulsive disorder.
I’m no longer involved with the ASD world.