What do phrenologist study?

Phrenologists were 19th-century doctors who believed that they could determine a person's personality and character traits by studying the shape of their head.

They believed that different areas of the brain were responsible for different personality traits, and that these areas would enlarge or shrink in size depending on how much they were used.

By feeling the bumps and ridges on a person's head, a phrenologist claimed they could determine which personality traits were dominant in that person.