State- and trait-greed, its impact on risky decision-making and underlying neural mechanisms.

We investigated whether greed would predict risky decision-making and recorded neural responses during a monetary gambling task using the electroencephalogram. We found that individuals high in trait-greed took higher risks to maximize monetary outcome. Furthermore, this relation was moderated by state-greed; specifically, trait-greed had a stronger impact on risky decision-making when activated by situational characteristics. On the neural level, greedy individuals showed a specific response to favorable and unfavorable outcomes. Specifically, they had a reduced feedback-related negativity-difference score to these events, indicating that they might have difficulty in learning from experience, especially from mistakes and negative feedback. It is concluded that greed may explain risky and reckless behavior in diverse settings, such as investment banking, and may account for phenomena such as stock market bubbles.