What Is Phrenology?

Definition and Principles of a Pseudoscience

Close up of Phrenology head diagram
Close up of Phrenology head diagram.

 Tetra Images / Getty Images

Phrenology is a pseudoscience that uses measurements of the human skull to determine personality traits, talents, and mental ability. This theory, developed by Franz Joseph Gall, became popular in the 19th century during the Victorian era, and its ideas would contribute to other emergent theories such as evolution and sociology. Phrenology is considered a pseudoscience because its claims are not based in scientific fact.

Key Takeaways: What Is Phrenology?

  • Phrenology is the study of personality traits, talents, and mental abilities as a consequence of skull curvature.
  • Phrenology is considered a pseudoscience due to lack of scientific support for its claims.
  • The theory has contributed to medicine because its basic premise is that mental functions are localized in areas of the brain.

Phrenology Definition and Principles

The term phrenology is derived from the Greek words phrēn (mind) and logos (knowledge). Phrenology is based on the idea that the brain is the organ of the mind and physical regions in the brain can contribute to a person’s character. Even at the height of its popularity, phrenology was controversial and is now considered discredited by science.

Franz Joseph Gall
Franz Joseph Gall.  Photos.com/Getty Images Plus

Phrenology is largely based on the ideas and writings of the Viennese physician Franz Joseph Gall. Other proponents of this pseudoscience were Johann Kaspar Spurzheim and George Combe. Phrenologists would measure the skull and use the bumps of the skull to determine characteristics of a human. Gall believed there were faculties of the mind that could be categorized and localized in distinct regions, called organs, of the brain. He mapped out 26 organs with vacant inter-spaces. Spurzheim and Combe would later rename these categories and divide them further into more areas, such as cautiousness, benevolence, memory, time perception, combativeness, and form perception.

Gall also developed the five principles on which phrenology is based:

  1. The brain is the organ of the mind.
  2. Human mental capacity can be organized into a finite number of faculties.
  3. These faculties originate from definite regions of the brain’s surface.
  4. The region’s size is a measure of how much it contributes to an individual’s character.
  5. The ratio of skull surface and contour of the brain surface is sufficient for an observer to determine the relative sizes of these regions.

In 1815, the Edinburgh Review published a scathing critique of phrenology, which brought it to the public eye. By 1838, after Spurzheim refuted the points in the Edinburgh Review, phrenology gained a larger following and the Phrenological Association was formed. At its beginning, phrenology was considered an emerging science, giving newcomers the opportunity to make new advances quickly. It soon spread to the Americas in the 19th century and quickly became successful. A big American proponent was L.N. Fowler, who would read heads for fees and lectured on the topic in New York. Unlike the early version of phrenology, where scientists were more focused on establishing its veracity, this new form of phrenology was mostly concerned with head readings and discussing how this relates to race. Some began using phrenology to promote racists ideas. It is Fowler’s work that would become the phrenology, racial concerns and all, we know today.

Gall's Faculties

Gall created 26 faculties of the brain, but the number increased over time as followers like Combe added more divisions. Practitioners reading heads would feel the bumps of the skull to see which of the areas laid out by Gall were more prominent to determine personality traits. This was used practically to give prospective career advice for young children, to match compatible lovers, and to ensure a potential employee was honest.

Phrenologist measuring a head
A phrenologist, who reads the 'bumps' on people's heads, demonstrating how to measure a head to a class of schoolgirls (circa 1937).  Hulton Archive / Getty Images

Gall’s identification methods were not very vigorous. He would arbitrarily select the location of a faculty and examine friends with that characteristic as proof. His early studies featured prisoners, from which he identified “criminal” areas of the brain. Spurzheim and Gall would later divide the whole scalp into more broad regions, like cautiousness and ideality.

His original list of 26 organs are as follows: (1) instinct to reproduce; (2) parental love; (3) fidelity; (4) self defense; (5) murder; (6) cunningness; (7) sense of property; (8) pride; (9) ambition and vanity; (10) caution; (11) educational aptness; (12) sense of location; (13) memory; (14) verbal memory; (15) language; (16) color perception; (17) musical talent; (18) arithmetic, counting, and time; (19) mechanical skill; (20) wisdom; (21) metaphysical lucidity; (22) wit, causality, and sense of inference; (23) poetic talent; (24) good-nature, compassion, and moral sense; (25) mimic; (26) and sense of God and religion.

Why Is Phrenology a Pseudoscience?

With no scientific support for its claims, phrenology is considered a pseudoscience. Even during its most popular era, phrenology was heavily critiqued and largely dismissed by the larger scientific community. John Gordon, who wrote the scathing critique of phrenology in the Edinburgh Review, ridiculed the “presumptuous” thought that feeling bumps could determine personality traits. Other articles went so far as to state that the terms phrenologist and fool were synonymous.

More recently, University of Oxford graduates conducted an empirical study to rigorously vindicate or debunk the claims of phrenology. Using MRI, scalp curvature to brain gyrification (gyri are brain ridges), and scalp measurements to lifestyles, the researchers concluded that there was no evidence to support that scalp curvature relates to individual traits or that a phrenological analysis produced any statistically significant effects.

Phrenology's Contribution to Medicine

Phrenology's largest contribution to medicine is that the early ideas proposed by Gall sparked interest in the scientific community about understanding the human mind and how it relates to the brain. Despite having been debunked by advances in neuroscience, some ideas posited by phrenologists have been confirmed. For instance, the idea that mental functions are localized in areas of the brain's cerebral cortex has been supported. Modern brain imaging has allowed scientists to localize functions in the brain and some speech disorders have been correlated with specific atrophied or lesioned areas of the brain. Gall’s proposed faculty for verbal memory was close to Broca’s and Wernicke’s areas, which are now known to be important areas for speech.


  • Britannica, The Editors of Encyclopaedia. "Phrenology." Encyclopædia Britannica, Encyclopædia Britannica, Inc., 1 May 2018, www.britannica.com/topic/phrenology.
  • Cherry, Kendra. "Why Phrenology Is Now Considered a Pseudoscience." Verywell Mind, Verywell Mind, 25 Nov. 2018, www.verywellmind.com/what-is-phrenology-2795251.
  • Jones, Oiwi Parker, et al. "An Empirical, 21st Century Evaluation of Phrenology." BioRxiv, 2018, doi.org/10.1101/243089.
  • "What Did Phrenologists Actually Do?" History of Phrenology on the Web, www.historyofphrenology.org.uk/overview.htm.
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Bailey, Regina. "What Is Phrenology?" ThoughtCo, Aug. 29, 2020, thoughtco.com/phrenology-definition-4688606. Bailey, Regina. (2020, August 29). What Is Phrenology? Retrieved from https://www.thoughtco.com/phrenology-definition-4688606 Bailey, Regina. "What Is Phrenology?" ThoughtCo. https://www.thoughtco.com/phrenology-definition-4688606 (accessed March 24, 2023).