Paraphrased:
The narcissist’s smirk is a subtle but telling expression that occurs when a narcissist experiences pleasure from manipulating or deceiving someone.
For narcissists, the smirk usually reflects contempt, which is a deep-seated disdain or lack of respect towards others. For narcissists contempt is tied to their belief in their own superiority. They view others who do not serve their needs as worthless or beneath them, showing a complete disregard for how their actions impact those around them.
Narcissism is a somewhat multidimensional trait with gradients of intensity. Who told you that it’s a binary classification?
https://www.researchgate.net/publication/346546680_Untangling_the_associations_that_narcissistic_admiration_and_narcissistic_rivalry_have_with_agency_communion_and_romantic_commitment/figures?lo=1
a lifetime of dealing with narcissists
Autism is a spectrum as swell but again, there is no such thing as a half autist
There’s people with more pronounced autistic traits and those with less pronounced ones. There isn’t half an autist, but there can be someone whose autistic traits’ intensities are near the middle of those of a person who clearly is autistic and those of a person who clearly isn’t.
The categorical nature of diagnoses does not reflect the underlying phenomena, it reflects arguments about healthcare resource allocation. The actual phenomena are more nuanced