Let me start from the beginning.
The younger you are, the easier it is for you to learn things, in an evolutionary psychology sense. The name for this ease and desire to learn things is “curiosity,” and children are very curious. Toddlers will put things in their mouths, out of curiosity, because their mouths are the most sensitive part of the body. Children will focus on so many things that adults have learned to ignore.
Why do kids like to watch movies over and over and over again? Because it feels to them like each time they watch the movie is new. Each time they notice things that they didn’t notice the first time, or forgot, or see themes that haven’t gotten boring to them. The adult views the plot as a cohesive whole. It takes more work to give the adult a sense of novelty. The adult is interested in deeper subtitles that children wouldn’t notice. Adults don’t revel in what have become familiar sensations, they just say, “I get it, moving on.”
The brain processes thousands of inputs. Tons and tons of data is constantly streaming in from the sense organs. It would be impossible to process it all. Therefore, the brain develops the ability to discriminate. It does this in a few ways. First, the brain ignores a lot of data that comes in from the senses, because it is not relevant. For example, research in-attentional blindness. Second, you sort sense data into discrete objects. We do not need to think about how every chair is unique, instead we store the abstraction “chair” which we reapply to every chair we come across, unless it is atypical. Third, we clump entire processes together, so an event like driving to work is almost automatic and remembered as one action, when in fact it was comprised of many sub-actions.
Part of the way we learn to do this is socialization. We learn from society what to pay attention to. We learn from culture how to categorize objects. We learn from culture what behaviors we should engage in. We are mimetic creatures. We copy those around us in order to develop the skills to process data. This is powerful, but this is also very limiting. By perceiving the world this way, we are limited into viewing everything through the prism of pre-constructed categories and prior lexicons. We are less able to notice certain patterns.
The impact of psychedelics is interesting, because it causes these mechanisms to break down. I have never used psychedelics, but I have been told by people who have that they break down pre-existing categories. You “forget” how you are “supposed” to categorize objects. You forget how you are supposed to clump events into a timeline. Psychedelics cause you to be fascinated by detail you otherwise would not notice, because it temporarily undoes the mental shortcuts that are wired in.
Now I’ll talk about autism. I want to say at the start that these are just things to help me conceptualize how autism works, it might not necessarily be true all of the time. I will sometimes use the term “autist,” when I am “supposed” to say “person with autism.” Person-first language, or rather, the forceful obligation to use it, is an example of how people use subtle social signals in their language and social shaming mechanisms, in the same way people use posture to assert dominance. This is non-explicit and inherently social. Autists are bad at that type of thing, so I think it’s disrespectful to force speech-code-like norms when discussing them.
Social Reciprocity: An autist has a poor mimetic ability. The technical term for this is social reciprocity. They will not as easily be socialized into seeing the world a particular way, adopting particular behaviors, and so on. Because mimicry is how we learn to process the world, autists therefore see the world differently. They do not operate with less abstraction, but they operate with different abstractions, that do not align with existing cultural abstractions.
Tantrums: Autists often have trouble figuring out what to focus on or pay attention to. They will pay attention to different things than they are supposed to. The reason autists throw tantrums is they can not cope with the amount of sensory data they are taking in. It is difficult to process loads of information. The kinds of autists who throw tantrums can’t deal with the sensory overload, because they have not learned that ability from others. Others have developed their own proper coping strategy for those types of situations. Fidgeting can be seen as a type of coping strategy.
Mind Wandering: Autists will get distracted, and have difficulty “focusing.” Sometimes autistic people have ADD. They can focus fine, but only on the things they find interesting; they just do not focus on the things they are supposed to be focusing on. Neurotypicals are more socialized and therefore are inclined to simply focus on what others are focusing on. This also correlates with a propensity to daydream, or what is better termed “mind wandering,” where you are disembodied, “in your head;” this occurs because how you process information is so discordant with everyone else that you do not have an outlet to let your ideas out of your head.
Ticks: It is the same thing with sensory issues. Autists can be very bothered by certain sensations, because they cannot help but notice some issue with that sensation, even obsess over it, when other people do not even notice it. Autists have OCD like symptoms. A compulsive behavior is a coping mechanism to deal with that sensation. OCD is a failure of the brain to “clump” processes into an action with a clear start and end. Instead every processes is dissected into subcomponents, and if one piece is strange it can trigger neurosis, while neurotypicals would not notice. Avoidance is another strategy for dealing with bothering sensations; autistic people will have an irrational distaste for certain things.
Obsessions: When learning a topic with a lot of complexity, it is difficult to know when to stop. Neurotypicals will know when to say, “ok, I’ve learned enough about that subject, now time to stop.” They are using certain socially imparted heuristics about what level of knowledge is optimal for their position. Autists do not have this gauge. When faced with an issue with great dearth of complexity, an autist will sometimes become obsessed, and want to learn absolutely everything. This kind of also explains why autism is associated with obsessively sorting, ordering, listing, and categorizing things. They cannot say, “the existing list and order is sufficient.” There are an exponentially large number of ways to hypothetically organize a group of objects, so most people will learn to ignore this complexity. Autists on the other hand will want to be as thorough and vigorous as possible.
Age: Autistic people often act much younger but also much older than they actually are. They act younger because they have trouble with attention in the way children do, but they also act older, because an autistic person may find something very interesting that others their age do not find interesting, because society says that you only become interested in that thing when you get older. Autism also changes as you grow older; this is why it is sometimes erroneously considered a “childhood disease;” getting older changes your attention.
Lack of interest in others: Guide books on autism most commonly talk about avoidance of eye contact, lack of interest in others, problems with verbal communication, failure to understand relationships, and so on. I want to emphasize that social interaction is inherently difficult, and being able to do it well is actually the peculiar thing. Imagine teaching a machine to do socialization. There are so many things you have to know how to do. You have to juggle so many considerations to maintain friendships, it is a miracle most people are born with that knowledge. Think of a group conversation. There is a different person talking all the time, and the conversation is constantly moving around from topic to topic. At every point, you are faced with a difficult problem: you need to figure out what to pay attention to, when to talk, and what to respond to. There are no objectively correct, teachable solutions. If you are a child in a classroom, you have no choice but to engage with that world of conversation, or get left behind, to be known as the kid with no friends. Some kids are simply developmentally late, and develop strategies to catch up later. Others have communication problems their whole lives.
Intelligence: Intelligence has a lot to do with your ability to quickly input and process lots of information. Many autists are of very low intelligence. Many autists are not. Intelligent autists can quickly input and process loads of information, but they do so differently, because they have not copied how others do so. Autistic people may behave awkward or strange, because strange means different than usual, and autists have a poor mimetic ability.
If you know someone who experiences one of the things I’ve listed here some of the time, it doesn’t mean they have autism. If they experience most of the things listed here most of the time, they might have autism. This list mostly pertains to high-functioning autism. You won’t need a list like mine for diagnosing low-functioning autism, because it is pretty obvious.