The Light Triad practices compassion, empathy, and altruism (cooperation), as opposed to the Dark Triad, which is driven by competition, aggression, and dominance (winning).
While both groups tend to make slightly higher than average earnings, those with Light Triad behaviors tend to do better long-term because, as Robert Greene says, they realize there is more than one side to the game.
Simplistically, Light Triad practices self-awareness, resulting in compassion, while the Dark Triad wins by condemning others.
Interestingly, meditation enhances self-awareness and dissolves egoism (self-centeredness) through self-monitoring.