How can we explain the variations and similarities of Palaeolithic art? Are we to suppose that European artists conformed to one great evolutionary sequence over 20 millennia? Or is the variation geographical, ideological or social? The author begins to address these big questions by deconstructing over 900 images of the horse, the animal most commonly depicted in European caves. He finds it possible to distinguish variations due to differences in live animals and due to differences in methods of representation – allowing the isolation of those few differences due to style. Applying this to a case study at Parpalló in Spain, he notes that the local sequence of horse images correlates with other cultural changes. Here is a method of great potential for revealing conservative and innovative trends.