Or you need to identify those who aren't behaving properly (sickness or other resource intense disability) and should be outcast from the group (something we don't need to do today, but the right wing narrative insists that need to do)
Actually, tribal humans tend to support people with disabilities, even severe ones. It's only feudal and capitalist societies that treat disabled people with cruelty. It isn't natural.
I was thinking psychopath. Someone who tries to blend in and act normal but never quite gets it. We have no problem be horrors to other species, but early humans couldn’t afford a psychopath willing and wanting to kill their own tribe.
Psychopath is just Latin for mentally ill person. Someone suffering from depression is a "psychopath", and no, depressed people aren't dangerous. What the fuck is wrong with you?
Even though that's what the latin translation is, that's not what the word means. The definition is "Psychopathy, or psychopathic personality is a personality construct characterized by impaired empathy and remorse, and bold, disinhibited, and egocentric traits masked by superficial charm and the outward presence of apparent normality".
Okay, first of all: the DSM is used primarily in North America. The majority of the world uses ICDM.
Secondly, the DSM has gone through many iterations and changes. For instance, DSM-I and -II contained psychopathy as a mental illness. It was replaced by ASPD in DSM-III. What we term today as "major depressive disorder" was also introduced in DSM-III. Did depression not exist prior to the third DSM? Did ASPD not exist? Does psychopathy not exist now that it has been replaced by ASPD?
Thirdly, there's so much bloody overlap in conditions listed in the DSM that you could present two psychiatrists with the same list of symptoms and they would diagnose two different disorders. And to my mind, this lends more credence to the first DSM's principle classifications of psychotic, neurotic, and behavioural disorders.
To summarize, the DSM is regional and therefore cannot be applied globally. It describes medical conditions and those medical conditions can be redefined at any time. And it is borderline unreliable due to diagnostic confusion and overspecification. In short, the presence or lack thereof of some cluster of symptoms in the DSM is not an indicator of the existence of a condition.
The DSM removed it because it was fake. Early psychologists believed in it, and over time they were proven wrong, so the official materials were revised.