The "rotten-to-the-core" assumption about human nature espoused so widely in the social sciences and the humanities is wrong. This premise has its origins in the religious dogma of original sin and was dragged into the secular twentieth century by Freud, reinforced by two world wars, the Great Depression, the cold war, and genocides too numerous to list. The premise holds that virtue, nobility, meaning, and positive human motivation generally are reducible to, parasitic upon, and compensations for what is really authentic about human nature: selfishness, greed, indifference, corruption and savagery. The only reason that I am sitting in front of this computer typing away rather than running out to rape and kill is that I am "compensated," zipped up, and successfully defending myself against these fundamental underlying impulses.
In spite of its widespread acceptance in the religious and academic world, there is not a shred of evidence, not an iota of data, which compels us to believe that nobility and virtue are somehow derived from negative motivation. On the contrary, I believe that evolution has favored both positive and negative traits, and many niches have selected for morality, co-operation, altruism, and goodness, just as many have also selected for murder, theft, self-seeking, and terrorism.
More plausible than the rotten-to-the-core theory of human nature is the dual aspect theory that the strengths and the virtues are just as basic to human nature as the negative traits: that negative motivation and emotion have been selected for by zero-sum-game survival struggles, while virtue and positive emotion have been selected for by positive sum game sexual selection. These two overarching systems sit side by side in our central nervous system ready to be activated by privation and thwarting, on the one hand, or by abundance and the prospect of success, on the other.