Thank you, @SRSAutistic. These are all questions I want answers to, too. I've been pondering this a lot lately and was actually thinking of starting a thread like this.
Here are my best guesses for answers. Keep in mind that I'm generalizing and "right in general" means "wrong about specifics".
I think that special interests start out as a topic in which we feel comfortable. I started out with a specific list of things I am comfortable talking about. Science was one, religion was another. But outside of those topics, I couldn't hold a conversation - I just wasn't comfortable talking about them. Slowly, I added more topics.
Since we're comfortable with a more limited set of topics, we will spend more thinking about and participating in them. That leads to learning much more about a topic than the average person.
I think that "comfortable" and "uncomfortable" are also euphemisms for symptoms of anxiety. Other subjects cause anxiety, but special interests do not. They are our own personal safe spaces. That also leads to a stronger devotion to them than other people have, since they have more options (or "areas of comfort").
I had heard once that anxiety is about 90% correlated with autism (from rough memory - don't quote me). If special interests are anxiety coping mechanisms, then I think the correlation is much higher than 90%.
...so that's my best attempt at figuring it out. I really would like to see this formally studied.
Here are my best guesses for answers. Keep in mind that I'm generalizing and "right in general" means "wrong about specifics".
I think that special interests start out as a topic in which we feel comfortable. I started out with a specific list of things I am comfortable talking about. Science was one, religion was another. But outside of those topics, I couldn't hold a conversation - I just wasn't comfortable talking about them. Slowly, I added more topics.
Since we're comfortable with a more limited set of topics, we will spend more thinking about and participating in them. That leads to learning much more about a topic than the average person.
I think that "comfortable" and "uncomfortable" are also euphemisms for symptoms of anxiety. Other subjects cause anxiety, but special interests do not. They are our own personal safe spaces. That also leads to a stronger devotion to them than other people have, since they have more options (or "areas of comfort").
I had heard once that anxiety is about 90% correlated with autism (from rough memory - don't quote me). If special interests are anxiety coping mechanisms, then I think the correlation is much higher than 90%.
...so that's my best attempt at figuring it out. I really would like to see this formally studied.