Phrenology. Drawings of the profiles of men's heads during a phrenology study of criminals. Phrenology was an attempt to relate physical characteristics of the head and face to behaviour and intelligence. Despite the fact that the theory was incorrect, many attempts were made to correlate head shapes and behaviour during the 19th century. This illustration formed part of a study of 1000 convicted men in Pentonville jail in London, Great Britain, by Dr V. Clarke. Clarke concluded that many criminals had a 'peculiar head and face' with marked asymmetries. Image taken from The Criminal (1895) by Havelock Ellis.