People seem to have flaws in their thinking that are like the flaws in Plato's thinking when he came up with the theory of forms. To an extent this is an inevitable consequence of using language, but people really ought to be aware of the fallacies that this way of thinking causes.
What I'm specifically referring to is viewing categories as rigid. Take autism for example:
The broader autism phenotype is a blurry subjective category with unclear borders. Some people in this category qualify for an autism diagnosis but are less likely to get one if they're perceived as female or some other marginalized group. Psychiatrists can disagree on whether they should get a diagnosis or what exact diagnosis should be given. This is complicated further by the fact that it is inherently subjective whether anyone meets certain diagnostic criteria and diagnostic criteria can change over time.
Yet people will make the false claim that you are "either autistic or you're not". This is fallacious platonic thinking. It presumes that there is a perfect archetype of Autism™ that people either have or they don't have. That's not how psychiatry works. It is a social construct that maps people's minds. And the map is not the territory.
