From DailyWritingTips.com:
What’s the difference between social and societal? Not much, but enough that you may become the victim of social stigma if you ignore subtle societal signals.
Societal is the pedantic alternative to social. . . .
I couldn’t agree more, having read hundreds of teeth-grating essays filled with “societal” this and “societal” that. Please, please, please: just say “social”!