What I have observed in my short forty years of existence, is simple, we humans as Kabbalah teaches, ultimately boil down to two principle realities, the first is pleasure – 99% of what we do is to gain a pleasure and the corollary of pleasure, which is to not feel pain – now as we have different souls in us, hence desires for different pleasures (and their corollary pain) hence, we instinctually are driven towards the pleasure of goodness and kindness and the corollary pain of when things are bad for others; the pleasure of instinctual desires, be they food, drugs, music, even intellectual ideas, for as a human also has an intellectual soul, the very notion of wisdom, is pleasurable (which obviously somewhat depends on the strength of this soul) but worst of all, we actually have a demon whose desire is to be better than others, hence we get a opposing pleasure (to the Divine soul) in the subjugation of others (also the source of anger, jealousy, hate etc.)