When you say "ASPD/autism" do you mean "ASD/autism"? ASPD is something very different (antisocial personality disorder, which sometimes used to be called psychopathy / sociopathy).

My understanding of the term 'spectrum' in this context is less "a scale from 0-100%" and more "a collection of traits which, if you have enough of them, would suggest you fit into this larger category".

In terms of being being able to navigate social situations, look up 'masking'. Many people on the spectrum learn to behave (sometimes very effectively) in 'normal' ways in social situations but it's a set of learned scripts and behaviours rather than being instinctive.