The approach/inhibition theory of power proposes that elevated social power increases the experience and expression of positive emotions and that reduced social power increases the experience and expression of negative emotions (Keltner, Gruenfeld, & Anderson, 2003). The evidence to date for these proposed relationships is correlational. Studies that have attempted to find a causal link between power and emotions have failed to do so. The current study manipulated social power in 61 three-person groups that engaged in a meaningful discussion (explanations for poverty in the US) that produced disagreements and strong emotions. High power individuals experienced and expressed more positive emotions and less anger than low power individuals did. High power individuals were also more likely than low power individuals to openly express their opinions during the group discussion. Implications for theory and future research are discussed. Copyright © 2006 John Wiley & Sons, Ltd.