When I was in high school, people still thought that I was a freshman when I was a senior. I think that it could be a mix of how we act (which tends to be "childlike" to some) and, possibly, that we age slower. Maybe it could also be that while people are trying to look younger (or older, depending on their age in some societies, especially in the US), we just don't care. It seems that most aspies are slightly (or majorly) oblivious to current trends, especially with fashion. People who go to tanning beds regularly tend to develop wrinkles earlier and look a bit older than they really are. I've never regularly put on makeup or have tried to get the newest creams and glamour products or have ever gone tanning. These factors probably have to do with how old or young you look. I think that I personally look a lot younger than I am (at 21 years), even for most aspies, is that I go running all the time. I've been involved in cross country running and track & field since middle school. I'm still involved in track and cross country in college. I definitely think looking older or younger has to do with many variables, as with almost anything.
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I'm 24 years old and live in WA State. I was diagnosed with Asperger's at 9. I received a BS in Psychology in 2011 and I intend to help people with Autistic Spectrum Disorders, either through research, application, or both. On the ?Pursuit of Aspieness?.