The celebrated French criminologist Alexandre Lacassagne, for instance, had a different take to Lombroso on the matter of tattoos.

He believed that the shape of a person’s brain held clues as to their personality and that it would also influence the shape of their skull. He believed that people were born with "moral and intellectual faculties," that these faculties were contained in the "organs" of the brain, and that a study of the skull could ascertain which faculties in the brain were the strongest. Considered a pseudoscience today, phrenology once claimed to predict a person's character and mental traits based on the shape of their head. By the 1840s there were more than 28 phrenological societies in London with more than 1,000 members.Despite its defunct status, phrenology has greatly influenced the development of neuroscience, notably the idea that certain functions are controlled by certain regions of the brain and the existence of white matter. A phrenologist demonstrates techniques used to "read" the bumps on a person's head to determine their character, 1937. From absolute and relative sizes of the skull the phrenologist would assess the character and temperament of the patient. Spurzheim took Gall's ideas to the United States, where they spread quickly among curious Americans. Long before neuroscience, phrenology claimed to have the power to determine who was afflicted with badness and who was suffering from madness.

One such adept was Scottish lawyer and phrenologist George Combe (1788–1858), who wrote about this pseudoscience in various books, including Elements of Phrenology, which he published in 1824.Though phrenology has been debunked, it's fascinating to see what people once thought certain skull shapes could tell us about someone's loyalty, masculinity, honesty, and more.