Yes, it's the opposite to "anti-social behaviour". So your phrase is used to describe someone who behaves in public... errr, like a normal human. :-/

It is the opposite of anti-social, which means that a person exhibiting "sociable behavior" is outgoing, and makes an effort at meeting people and helping them feel at ease through friendly actions, smiling, and pleasant conversation.

yes i heard it before from my professor. cowboy...

Rules, norms, custom, habits dictate a person's social behaviour. It is usually defined by the society that they live in.

yes..it is a psycologic term, i think!