We ran two experiments to test whether people value objects more highly when they obtain those objects due to exemplary performance at a task. In the first, subjects who believed they had obtained a prize due to their performance on a classroom exercise valued it more highly than those who believed they had obtained it by chance. In the second, subjects who obtained a prize due to exemplary performance on a task valued it more highly than those who obtained it due to their poor performance. In both experiments, this ‘source dependence’ effect is approximately equal in strength to the endowment effect, which compares the valuation of subjects with and without the prize. We suggest a possible explanation for this source-dependence effect based on associationism, and rule out two alternative explanations.