Sitting in Michael's Lap
I'm afraid that in order to answer this question, I need a more precise definition of "mean."
If you refer to the tendency to center one's actions about the goal of furthering one's self-interest, I'm afraid you've hit upon the primal survival instinct. Yes folks, we still are animals, and will follow our instincts if not consciously striving to do otherwise.
Fortunately, one of the very things that make us unique as a species is our ability to ignore or overpower our selfish instincts, thereby sacrificing some portion of our own self-aggrandization to serve the needs of some "greater good." Ideally, the beneficiary of this sacrifice is society as a whole; one person's gift helps another, or several others, and they feel compelled to reciprocate with their own sacrifice. Everyone's happy, la-la-la ....
Problem is, there's still those instincts pecking at our morality. Then there's the general degradation of society as a whole; most often perpetuated by those in power (read: those with money). So the norm shifts back to selfish ... to violence, perhaps. We are bombarded with it every day -- TV, music, even on the streets. Our governments are so busy squabbling with one another over this bit of land or that field of oil that they don't see the damage being sown right under their noses.
Um ... I just realized I went off on a major tangent here but I really don't feel like editing so ... welcome to my madness.