Some of mine have a "blank stare" and some don't. It helps that my mother was good at getting candid shots where I was looking natural. Examples follow.
Here's some with a "blank stare" (I don't fully know what one is so I'm going by what others say):
Here's some without:
I think basically what it is, is that what people call a "blank stare" is my default facial expression, even today, and that expression has gone unchanged my entire life. However, when I'm having other facial expressions, then that default expression disappears, usually briefly, until eventually the default expression comes back. I used to actually be better at doing facial expressions on purpose than I am now. (It sort of went... first I couldn't, then I learned to, then I lost most of what I learned.) So most of my photos these days still have that "blank stare" look. But it's far from a universal thing in autistic people, and plenty of autistic people don't have that expression ever in their old photos. It all depends on the person. (Oh and I'm autistic but technically not "aspie". I hate making the distinction because I don't really like the distinction, but to me autistic is a more universal term that includes me and "Asperger" is a non-universal term that doesn't include me. So sometimes I mention this and sometimes I don't.) The amount of photos is so you can see it throughout my childhood and not just at one age.
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"In my world it's a place of patterns and feel. In my world it's a haven for what is real. It's my world, nobody can steal it, but people like me, we live in the shadows." -Donna Williams