I think selfish is the wrong word to use, people are less community minded for a variety of reasons, working late hours, having personal difficulties to deal with, stress, social anxieties, financial problems, fears of the changing world and health problems.
Perhaps you need to give some examples in what you regard as selfish, from my experience when you talk to people you realise that some have lots of troubles of their own, some quite devastating and you can see why they have become introspective.