Abstract
Large samples of children in southern Mexico representative of the urban middle class, urban poor, and a rural Indian village participated in four experiments. These were designed to assess cooperative and competitive motivation under the following conditions: (1) simple altruism, (2) work output, (3) solution of a problem in which competition minimized individual reward, and (4) solution of a problem in which competition maximized individual reward. Significant differences between groups were obtained in Exps. III and IV with the urban middle-class children proving to be much more competitive than their urban poor and rural counterparts.