Allistic folks, in contrast, make sense of the world in a very top-down fashion. They’ll enter a new environment, such as an unfamiliar restaurant, take a quick look around, and jump to reasonable conclusions about how to order, where to sit, what kind of service to expect, and even how loudly they should talk. Their brains will immediately begin to filter through sounds, lights, and other stimuli, and adjust accordingly. They might notice a clanging pinball machine in the corner for a moment, for instance, but soon habituate to it, and become able to ignore it. When the waiter approaches, they probably can chat without much difficulty, even if something unexpected gets said or the item they planned to order is sold out. They don’t rely on memorized conversational scripts, and they don’t have to carefully parse every single piece of data they encounter to make sense of it. They can wing it.
Autistic people, on the flip side, don’t rely on knee-jerk assumptions or quick mental shortcuts to make our decisions. We process each element of our environment separately, and intentionally, taking very little for granted. If we’ve never been in a particular restaurant before, we may be slow to make sense of its layout or figure out how ordering works. We’ll need really clear-cut indications of whether it’s the kind of place where you sit down and get table service, or if you’re supposed to go to a counter to ask for what you like. (Many of us try to camouflage this fact by doing extensive research on a restaurant before setting foot inside.) Every single light, laugh, and smell in the place is taken in individually by our sensory system, rather than blended into a cohesive whole. To cope with unpredictability, we analyze our experiences for patterns, and memorize rule sets: if the waiter says X, I reply with Y. When something unexpected happens, we have to carefully sort out how to respond. Too much change may cause us to become really exhausted, or to freak out.