Social Pressure is Real
This is very real, and often is used for evil. The school yard game of dare, which would quickly escalate to double-dog-daring, never bore much good. Yet, the assumption under which social pressure functions is actually good. It is simply the idea that conforming to the image of those whose relationship you value is a good thing. Example:
We often value the relationship of those who care for us, take an interest in our wellbeing, or provide for us. The signal is that they have our best interest in mind. If they do, we suspect that they might also be a good model of a person as well. Why not conform to them?
Here’s why. Not everyone who cares for us, takes an interest, or provides for us, is also modeling behavior that they want passed on. Most, while trying to live a perfect life, have their faults (a perfect life is rare, for the rest of us there is Grace). Nevertheless, any conforming that happens should ultimately be checked against values, lest we wake up one day a person we don’t recognize.