The aim of this research was to study the learning process using an objective and computerized task. The performance of 466 schoolchildren aged between 6 and 11 in a category learning task, the Category Learning Test (CLT), was examined. The results showed evidence of category learning throughout the trials for the whole sample, F(7, 469) = 29.979, p <.001. In addition, categorization performance improved with age, H(2) = 48.475, p <.001. However, there were old children that struggled with the task and young children that performed very well. The ability to learn the categories was related to the children’s behavior when trying to solve the task: the response speed (r = –.217, p <.01) and the organization index (r = .247, p <.01). Nevertheless, performance in the task and academic marks were not related. We discuss the impact of these findings on the promotion and improvement of learning in schools: an intervention to promote slowness and organization might help some children to learn.