All In My Head My Manual
Because the human head is the location of the thinking organ, it has been the subject of intense study. Some of the early modern research on the human head by German physician Franz Joseph Gall has resulted in the pseudoscience of phrenology, which reached its peak in the 19th century. It attributes character traits and mental abilities to the shape of the head. The measurement of the human head and skull, known as craniometry, gained popularity at the same time. Some, notably in Nazi Germany, have used these measurements and other comparative research as the underpinnings of racist, pseudoscientific theories.
The procedure of trepanation has also been advocated and practiced for pseudoscientific reasons.