The present research was designed to test the hypothesis that children woul
d compete more in tetrads than in dyads. Twenty-two pairs of male and 14 pa
irs of female target children (N = 72) played a competitive game in both te
trads and dyads. Consistent with the hypothesis, male target children compe
ted more in tetrads than in dyads. This hypothesis was not supported for fe
males, however. Analyses of the dynamics of tetrads and dyads further demon
strated that based on a global measure of smiling, the emotional atmosphere
was less positive in tetrads than in dyads. The causes and consequences of
interaction in different sized social groups are discussed.