I think this isn't true without some additional qualification? After all, all petty crime, vandalism, littering, aimless churlishness etc. is against social norms. I think I get what you mean though, but am also missing a term for that kind of social norm contravening.
Being against something simply for being a social norm isnt the same as having nonpressure to follow social norms. With theblatter you will still use your discretion but something being against a social norm wont weigh your decision as much as other factors.
@AmpBenzScientist generally speaking intelligent people are more likely to go against social norms. So while i dont think being gay means you are more intelligent i do think being openly gay tends to lean towards higher IQ people.