Gall, Franz Joseph (1758-1828), a German-born French anatomist, founded the pseudoscience (false science) of phrenology. Phrenology was based on the belief that different areas of the brain control different aspects of behavior. Gall believed that the skull could be mapped to show the locations of these areas, which he called organs. Some organs covered personality traits, and others controlled mental abilities.

According to phrenologists, a person's outstanding traits could be identified by bumps or bulges on the head. These swellings were caused by the enlargement of the organs related to each powerful trait.

Gall wrote, with Johann Kaspar Spurzheim, the first two volumes of Anatomy and Physiology of the Nervous System (1810-1820). The two parted company in 1813, and Gall finished the remaining two volumes himself. These volumes expounded his theories on phrenology. Gall lectured widely throughout Europe starting in the 1790's. He also traveled to schools, hospitals, prisons, and institutions for the mentally ill to gather evidence in support of his theories.

Phrenology was popular in Western Europe and North America during the early and mid-1800's. Many eminent political figures, philosophers, and artists subscribed to the theory, including the United Kingdom's Queen Victoria, U.S. President James Garfield, and the writers Edgar Allan Poe and the Brontë sisters. However, by the end of the 1800's Gall's assertions had been almost entirely discredited.

Scientists today know that a personality trait is not localized in any one area of the brain. Different parts of the brain have different functions, but the parts interact in a more complex way than phrenologists realized. Nevertheless, phrenology did help pave the way for the scientific study of personality, and thus for modern psychology.

Gall was born in Tiefenbrunn, near Pforzheim, Germany. As a boy, he was educated by an uncle who was a priest. He later attended schools in Baden and Bruschal. In 1777, he began studying medicine in Strasbourg. He earned his medical degree in Vienna in 1785.