Someone asked for adult autistic perspectives on why an autistic child would enjoy lining things up. After someone commented on the visual and tactile pleasure provided. I wrote:
For me, there's also a sense that this is how things want to go/ be. The pattern is there, calling the objects into it. Until the objects mesh with the pattern, there is discord. Discord resolves into pleasing harmony when the objects and the pattern are one.
Also, given the way my particular brain works, I find myself feeling
responsible for "helping" objects attain the pattern they "want."
That's how it feels. And when I follow through with arranging the
objects into the (correct) pattern, there is a pleasing sense of
responsibility accomplished. It's like a state of friendship between
me and the objects. We help each other out. I "do the right thing" by
them, and the world feels friendlier towards me.