The effects of two social contexts on the risk-taking of elementary boys on a shuffleboard task were investigated. It was predicted that Atkinson's motive-probability-incentive (M-P-I) model would be supported in the peer-competitive context. In that the success-oriented subjects would choose more goals with median Ps values than the failure-avoidant subjects, but that these two groups would not differ in this regard in the adult-evaluative context. These hypotheses were supported. A test was also made of Atkinson's recent prediction that performance will relate positively to summated motivation in the peer-competitive context but negatively to this variable in the adult-evaluative context. These predictions were partly supported, and the data were interpreted in terms of the inverted U curve postulated to hold between discriminative behavior and total arousal. The summated motivation measure is a combination of need for achievement, defensiveness and text anxiety. (Author/DB) (45pp.)