Well, there are a huge number of crimes I didn't commit today because I feel no particular impulse to commit them.

Well that's given; I meant other than crimes you don't want to commit in the first place.

And there's a smaller number of crimes I didn't commit today because I've internalized social prohibitions against them, such that even if the external threat of being punished or considered/treated a bad person were removed, I would nevertheless feel bad about doing them.

A heuristic, a learned behavior. As a rationalist I see value in getting rid of misapplied heuristics of that kind. It would puzzle me if this wasn't the default approach (of rationalists, at least). Granted, most of the social conditioning is hard or impossible or dangerous to remove...

Your answer sums up to "fear of repercussions that is active even when I know consciously there's nothing to fear". This is the standard (human) answer, and not very interesting.