Why do so many members of the speedrun community have autism?

Because only Autistic people can hyper fixate on something like a single video game long enough to be good at speedrunning it. What a stupid fucking question.

What a retarded question. That's like asking why so many autismos play fucking Runescape.

Certain activities in life draw certain personality types or disorders. Speedrunning is endless commitment to repetition. Of course it draw the autistic