Yeah, "thinks or reacts to things differently than most people" is way too broad.
It also shouldn't be a binary classifier. Some people are definitely "autistic", and some are definitely not, but many of the personality traits that define autism are continuous: e.g. some people are barely distracted by loud noises (normal), others are distracted by loud but not quiet noises (normal), others are distracted by specific quiet noises like chewing (autism?), others are very distracted by any noise even with noise-cancelling headphones (autism?).
I think people should just say "I have sensory issues" (or clarify "noise really distracts me"), "I'm bad at reading emotions", "my mood is really affected by others". And accommodations maybe do need to be binary (or graded), but should ideally be informal, and definitely be for specific traits instead of "autism": e.g. don't give someone who thinks methodically but isn't bothered by loud environments their own room (unless you give everyone that), but don't assign them vague tasks or they'll perform poorly.
You're right that sensory issues make up a small (optional) part of the diagnostic criteria for ASD under the DSM-5. And I agree that "autism" in popular discourse seems to be very flexible and inclusive, but the medical diagnostic criteria are much more specific. When someone does meet these criteria, there's something going on that isn't just a collection of unrelated peculiarities. This seems to be supported by the very high heritability of diagnosed ASD.
I would agree with you that there are issues caused by the wide range of presentations. It seems as though there's a tension between differentiation and unification at the various levels of scientific research, social understanding, social accommodation, etc. I expect things will get teased out over time.
> To meet diagnostic criteria for ASD according to DSM-5, a child must have persistent deficits in each of three areas of social communication and interaction (see A.1. through A.3. below) plus at least two of four types of restricted, repetitive behaviors (see B.1. through B.4. below).
Example (A.1):
> Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions
The medical diagnostic criteria, despite using technical language, are still vague: "deficits in..." has a wide interpretation. Furthermore, "at least two of the four" permits two people diagnosed with autism to have different symptoms: one child may only have limited interests and insistence on sameness, while another may only have "stereotyped" motor movements and hypersensitivity (and the specific interests, "stereotyped" behaviors, and hypersensitive stimuli can vary).
I've copied the required features from your linked document. With that said, I'd say most people tend to have every trait there to some extent. So I'm not sure that the medical criteria is as specific as you implied. It seems like the main criteria they use is that the symptoms cause significant impairment in your life.
---
Essential (Required) Features:
Persistent deficits in initiating and sustaining social communication and reciprocal social interactions that are outside the expected range of typical functioning given the individual’s age and level of intellectual development.
Specific manifestations of these deficits vary according to chronological age, verbal and intellectual ability, and disorder severity.
Manifestations may include limitations in the following:
Understanding of, interest in, or inappropriate responses to the verbal or non-verbal social communications of others.
Integration of spoken language with typical complimentary non-verbal cues, such as eye contact, gestures, facial expressions and body language.
These non-verbal behaviours may also be reduced in frequency or intensity.
Understanding and use of language in social contexts and ability to initiate and sustain reciprocal social conversations.
Social awareness, leading to behaviour that is not appropriately modulated according to the social context.
Ability to imagine and respond to the feelings, emotional states, and attitudes of others.
Mutual sharing of interests.
Ability to make and sustain typical peer relationships.
Persistent restricted, repetitive, and inflexible patterns of behaviour, interests, or activities that are clearly atypical or excessive for the individual’s age and sociocultural context.
These may include:
Lack of adaptability to new experiences and circumstances, with associated distress, that can be evoked by trivial changes to a familiar environment or in response to unanticipated events.
Inflexible adherence to particular routines; for example, these may be geographic such as following familiar routes, or may require precise timing such as mealtimes or transport.
Excessive adherence to rules (e.g., when playing games).
Excessive and persistent ritualized patterns of behaviour (e.g., preoccupation with lining up or sorting objects in a particular way) that serve no apparent external purpose.
Repetitive and stereotyped motor movements, such as whole body movements (e.g., rocking), atypical gait (e.g., walking on tiptoes), unusual hand or finger movements and posturing.
These behaviours are particularly common during early childhood.
Persistent preoccupation with one or more special interests, parts of objects, or specific types of stimuli (including media) or an unusually strong attachment to particular objects (excluding typical comforters).
Lifelong excessive and persistent hypersensitivity or hyposensitivity to sensory stimuli or unusual interest in a sensory stimulus, which may include actual or anticipated sounds, light, textures (especially clothing and food), odors and tastes, heat, cold, or pain.
The onset of the disorder occurs during the developmental period, typically in early childhood, but characteristic symptoms may not become fully manifest until later, when social demands exceed limited capacities.
The symptoms result in significant impairment in personal, family, social, educational, occupational or other important areas of functioning.
Some individuals with Autism Spectrum Disorder are able to function adequately in many contexts through exceptional effort, such that their deficits may not be apparent to others.
A diagnosis of Autism Spectrum Disorder is still appropriate in such cases.
"I'm autistic" could mean "I'm non-verbal and can't function without constant care", "I'm very good at hacking, but need help with basic things", "I can function independently, but tend to over-think and over-explain and can't read people's emotions", "I can read people's emotions but am overwhelmed by them, I'm also unusually soothed by ASMR", "I'm unusually irritated by ASMR"...and there's no boundary that separates "real" autism from almost normal with certain traits slightly elevated.
Idk. If someone can pinpoint a single cause, it is binary. Not that I think that's possible: the human mind is so poorly understood, a real cause-effect relationship is scifi.
> some people are barely distracted by loud noises ...
It's not an argument for a non-binary classification. The whole point is that that a symptom, even a group of symptoms, doesn't define autism. Sensitivity to noise is just one of those things that some group has managed to be associated with autism.
Its definition has been expanded significantly. If it continues, there'll be two types of people: autists and psychopaths.
Yes, the problem isn't that the definition isn't 100% formal. If "autism" meant "unusually sensitive to loud noise" (and presumably other symptoms get new labels) that would be reasonable. But it seems to mean "unusually sensitive to something OR unusually methodical OR unusually bad at reading emotions OR unusually affected by other's emotions OR ... ", and almost nobody has every symptom, but two people may have completely different symptoms while a third person has some from each.
If you just have one of the symptoms you shouldn't be diagnosed with autism.
I think a lot of people miss that the changes that combined a ton of stuff into autism was because we had a ton of different disorders that had super similar treatment plans, but it could cause issues when your doctor didn't know all of the related disorders to be able to know to try different treatment plans.
The combining was an acknowledgement that we don't know what causes these combinations of symptoms to occur but they seem to be related when certain combinations of them occur and these treatments can work to lessen the impact on the person experiencing it.
It also shouldn't be a binary classifier. Some people are definitely "autistic", and some are definitely not, but many of the personality traits that define autism are continuous: e.g. some people are barely distracted by loud noises (normal), others are distracted by loud but not quiet noises (normal), others are distracted by specific quiet noises like chewing (autism?), others are very distracted by any noise even with noise-cancelling headphones (autism?).
I think people should just say "I have sensory issues" (or clarify "noise really distracts me"), "I'm bad at reading emotions", "my mood is really affected by others". And accommodations maybe do need to be binary (or graded), but should ideally be informal, and definitely be for specific traits instead of "autism": e.g. don't give someone who thinks methodically but isn't bothered by loud environments their own room (unless you give everyone that), but don't assign them vague tasks or they'll perform poorly.