The effects of enforced rehearsal (ER), model-observation (O), and model-observation plus voluntary rehearsal (OVR) on private charitable behavior, both immediately following the experimental manipulations and after an interval of several days, were examined. The results indicate that where the motivational stakes are reasonably high, observation alone is not a sufficient eliciting agent. O Ss failed to evidence significantly more altruism than controls. This finding is interpreted as applying a needed corrective to the modeling research area, imposing a boundary condition on the efficacy of modeling. In general, girls gave more and were significantly more consistent in their giving than boys.