Résumé : We conducted an experiment to collect data on consumption decisions made by children of different age categories. In particular, our experiment involves unsophisticated discrete consumption choices,and we present a rationality test that is specially designed for the resulting choice data. Our firstconclusion is that, in general, the observed children's consumption behavior is largely irrational. Next, we also investigate the relationship between the degree of rationality and the children's characteristics.Specically, we use teacher based assessments on several personal characteristics to investigate whether and to what extent smart children tend to behave more rational. Here, our main conclusion is that it is important to recognize the multidimensional nature of intelligence to obtain a balanced insight into the effect of intelligence on rationality.