Crime Library: Criminal Minds and Methods

Bad to the Bone: All About Criminal Motivation


"I never knew I had an inventive talent until phrenology told me so. I was a stranger to myself until then!"Thomas Edison, (1847-1931), American inventor

Biological theories of crime causation, most of which were formulated during the 19th century, assumed crime was caused by inherited factors. Some scientists believed that criminal behavior could be traced to physiological origins. The idea that a person's character can be interpreted by looking at his or her face is derived from ancient times. Even today, we frequently hear expressions such as "she has the face of an angel" or "he looks like a nice guy."

One of the many phrenology journals to appear during the 19th century
One of the many phrenology
journals to appear during the
19th century

An Austrian physicist, Franz Gall (1758-1828), was the first to present these themes as a science. Gall believed that the shape of the brain and the skull could reveal an individual's personality and psychological development. This theory, called phrenology, became widely popular and was used for many years in Europe and America. During this time, phrenology journals, which interpreted human skull shapes into psychological profiles, appeared throughout the world. These books made entertaining reading and soon phrenology became the rage of 19th century intellectuals. Even Edgar Allen Poe was a believer in phrenology and examples can be found in some of his writings such as The Fall of Usher and The Black Cat. Some phrenologists claimed that it was possible to predict the aggressive nature of criminals by a simple skull examination.

Gall believed that the brain contained all the morals, sentiments and properties a person could have. He said that the form and shape of the human head correlates directly to the abundance or lack of certain personality traits. Thus, certain areas of the brain were the localities for aggressions, hostility, destructiveness and secretiveness. Depending on which phrenology expert was consulted, there were 27 to 38 regions on the head that were associated to personality traits. If these areas were expanded or more pronounced than a "normal" head, then that person would demonstrate more of those traits. Skull maps by the hundreds were devised that showed where these critical areas were located.

Another 19th century phrenology image depicting a comparison between a
Another 19th century phrenology image
depicting a comparison between a "good
mother" and the "unmotherly."

Other scientists joined the phrenology parade and the "new science", as it was called, became a sensation. Even politicians and judges became enamored with the possibilities of predicting human behavior. Attempts were made to legitimize phrenology by using it in America's courtrooms. In 1927, a well-known phrenologist, Dr. Edgar Beall was called in to perform a reading on Ruth Snyder, accused of murdering her husband. Dr. Beall decided that Snyder's chin "tapered like the lower face of a cat" which proved her "treachery" and "ingratitude." Her mouth was as "cold and hard and unsympathetic as a crack in a dried lemon." Beall's final analysis, after studying Ruth Snyder's face, was that she had "the character of a shallow-brained pleasure seeker...murderous passion and lust." These descriptions were printed in newspapers of the time and treated as fact.

Phrenologists also began to branch out into other areas of society. They were consulted in medicine, politics and used in the arts as well. Criminals were thought to have damaged brains that produced an over-abundance of aggression or hostility. Phrenologists believed this condition was caused by outside influences that stimulated the brain to overdevelop. These outside influences included lethargy, booze, masturbation and too much study as a child or too much religion. Criminals should be placed in a "moral hospital" where they would be taught good things and cut off from bad influences. Some phrenologists wanted to imprison people based on the results of a skull examination if it showed even a potential for hostility.

Gradually, phrenology began to fall from favor. Unscrupulous entrepreneurs and con men traveled the country, bilking people out of money and valuables with false readings. Phony "scientists" seemed to be everywhere, offering to give expensive lectures on the latest "advances" in the new sciences. Odd machines that automatically provided a phrenological reading of the skull began to appear at movie theaters and department stores. A person would sit in a chair and a metal helmet was placed on the head which measured bumps and crevices in the skull. A report would then print out a detailed reading of the patient's personality. One of these phrenology machines can still be seen today at the Museum of Questionable Medical Devices in Minneapolis.

By the 1930s, phrenology had come under heavy criticism on many different fronts. Physicians, psychologists, scientists and universities began to attack the entire concept of phrenology. Defects in Gall's theories were exposed. One of the major failings of phrenology was that it made no sense that soft brain tissue could cause indentations in the skull. Additionally, the regions of the brain assigned to specific personality traits varied from one phrenologist to the next. Finally, people realized there was no hard evidence to support any of Gall's theories.

Eventually, phrenology became quackery and the theorists moved on.