I'm not referring to the social pressure against, say, being gay in 1950. I'm thinking more along the lines of the social pressure against smoking in 1980. It's a clear preference, and everyone know it's a good idea, but you're not shunned for disobeying. (Admittedly, social pressure is really, really hard to calibrate. There's not enough in favour of charity right now, except in the occasional microcosm like LW, but overshooting is possible, and there's several real examples to point to).