Human beings are intensely social, which means behavior is often shaped by what others appear to believe, approve, or expect. Social influence can guide norms, encourage cooperation, and transmit culture, but it can also pressure people into conformity.

Much of everyday life—from fashion and speech to workplace behavior and moral courage—contains an invisible social layer. People do not just ask, 'What do I think?' They also ask, often unconsciously, 'What are people like me supposed to do?'

Reference:

Wikipedia: Social influence

https://en.wikipedia.org/wiki/Social_influence