If I take my skin color and type, stress level, all the illnesses I have had, kids I still think I look exactly my age. I had hard time to recognize people's age when I was younger, but I became a little bit better at it. So far I've never met anyone who looked significantly younger. People might seem younger, but if you look closer there're always going to be indicators of an actual age. I've met people who looked healthier for their age. People who take care of themselves, have no serious illnesses, or simply belong to certain racial group or mixtures or groups may appear younger but the closer you look the better you see that it's not really true. I had 2 friends, one was 100% (more or less
) Korean and another obviously had some Asian or native blood in her. They both seemed young for their age (one of the reasons was, they were trying to present themselves as younger people, so they dressed and behaved accordingly) but if you looked closer you would be able to see signs of aging appropriate for their skin and body type, etc., so in the end they pretty much looked their age. And I don't think it is an "Autistic trait" or "Asperger trait", because I just don't see any evidence proving it
and I think judgement depends on personal expectations of how people suppose to look like at certain age, people have different expectations so what looks "young" to one may not look the same to another. So I don't really see how it can be a trait. But then again, we have to specify what we're talking about, are we talking about an image a person presents or actual physical appearance?
I remember I watched one crazy show some time ago... something about dressing up people appropriately. There's a woman once, who dressed like a teenager. She claimed people thought she was 15, 16 or something like that, don't remember exactly. She actually was in her late 30s or 40s, I couldn't understand what she's talking about, to me she looked like a 40 years old dressed up in a 12 years old clothes. It all depends on what people pay attention to: image or actual physical appearance.