I find it exceedingly unlikely that increasing "stigma and fear" will reduce such behavior. For instance, out-of-wedlock births, teen pregnancy, divorce, etc. are all higher in more socially conservative societies — including when we compare the U.S. vs. Western Europe, or "red states" vs. "blue states" within the U.S. ...

I find it very likely that they will since social shaming is among the most powerful means a culture can employ to maintain norms.

Maybe fear and stigmatization do work, but the less socially conservative societies use other means of maintaining cohesion, ones that are more palatable to them?
The most, as they say, disfunctional groups in a society - such as ghetto youth - have rather illiberal and inegalitarian norms anyway, it's just that those norms involve violent and parasitic behavior rather than that of a decent, productive conservative community.