What are the distinguishing features of a social policy?

Your question required more definition. An individual problem (you have bad body odor) could also be a social problem since your ability to be with other people would be degraded. On the other hand an individual problem (I can't stand the sight of dogs because they scare me to death) is an individual problem and does not affect a group.

If I were you, I would define your question very specifically and give (made up) examples of what you are thinking. "Social problem" can either be you or your small group of friends or an entire nation. "Individual" can either be you only, or a small group of larger group that has no real impact on surrounding members. The word "problem" is, in itself, a problem in that one person's problem is another person's solution. My problem with not liking dogs is the SPCA's love. (In fact, I like dogs very much, by the way).

They way you have asked your question it can not be answered with a definitive response.