Abstract
Interindividual-intergroup discontinuity refers to the finding that groups are more competitive than individuals. Research on this phenomenon has typically compared interindividual and intergroup interactions in mixed-motive games where both players have equal power, neglecting power differentials that often characterize social interactions in everyday life. We had three key objectives. First, we tested whether the magnitude of the discontinuity effect varies depending on whether the players have equal or unequal power. Second, we compared the behaviour of high- and low-power players, correcting an imbalance in previous research, which has concentrated on high-power players. Third, we introduced a distinction between unequal-power stemming from differential control over the other player's outcomes versus differential control over one's own outcomes. Groups were more competitive than individuals and the magnitude of this discontinuity effect did not vary significantly between equal- and unequal-power settings. Further, regardless of whether the interaction was between individuals or groups, unequal (compared to equal) power conduced to competition. Finally, this greater competitiveness in unequal-power settings was due to the high-power players. Having high power (compared to equal or low power) increased competition in interindividual and intergroup interactions, irrespective of whether this power derived from greater control over others' or own outcomes.