Phrenology: measuring the skull to study the mind

April 3, 2024

Phrenology was a pseudoscience that defended that the shape of the skull gave information about the faculties and mental features of people. This movement was popularized in the 18th century by the physician Franz Gall and had a large following, although it lost relevance after a few decades.

In this article we will describe the history of phrenology, the basic postulates of this discipline and the conception of the brain that had the disciples of Gall. Finally, we will talk about the legacy of phrenology in modern neuroanatomy.

Related article: "History of Psychology: authors and main theories"

History of phrenology

Phrenological hypotheses did not arise in a vacuum, but were derived from previously existing conceptions. In particular, physiognomy enjoyed a certain popularity during the 18th century, which proposed that people's physical appearance could be used as a basis for analyzing their psychology, and Charles Bonnet influenced brain localization.

The German doctor Franz Joseph Gall (1758-1828) He began to give lectures on phrenology in 1796. It was his collaborator Johann Gaspar Spurzheim, also a key figure, who spread the word "phrenology", of which Gall renegade since he saw himself primarily as a physiologist and neuroanatomist.

Like mesmerism, phrenology extended as a probable scientific truth among the lower and middle classes of eighteenth-century Europe, very open to advances in different fields because of the influence of the French Revolution and the Enlightenment. Edinburgh became the nucleus of phrenology , and there the first phrenological society was founded.

In the 1840s, barely 40 years after its emergence, phrenology hypotheses had been discredited by the scientific community. However, interest in these practices spread to America and Africa with European colonization, and in many places they have resurfaced at specific moments, especially as a tool of racial domination.

Related article: "Morphopsychology: your facial features ... indicate your personality?"

Basic postulates of Franz Joseph Gall

Gall published in 1819 his key work: "Anatomy and physiology of the nervous system in general, and the brain in particular, with observations on the possibility of recognizing many intellectual and moral dispositions of man and animals by the configuration of their heads."

In this text, Gall described the six basic postulates of phrenology .

1. The brain is the organ of the mind

For phrenologists the mind was located in the brain; Today this idea, which was not new in the days of Gall, enjoys great popularity. This approach was opposed to the conception of mind as a manifestation of the soul, more widespread in the eighteenth century than today.

2. The mind is composed of faculties

The mind is not a unitary entity, but is composed of multiple faculties. In phrenology the concept "faculty" refers to the different specializations or tendencies of the mind , like ambition, perseverance or benevolence. Later we will make a list of the faculties described by Gall.

3. Each faculty is located in an organ

Gall considered that, since the mental faculties are different and unique, they should necessarily be located in separate "organs" of the brain. This postulate turns phrenology into a antecedent of localizationist theories on the functions of the central nervous system.

4. The size of an organ indicates its power

The relative size of each organ in comparison with the rest of the brain can be taken as a sign of the development of a certain faculty, according to phrenology. Likewise, an organ can be larger in one of the cerebral hemispheres than in the other.

5. The organs determine the shape of the skull

Gall said that during childhood development the bones of the skull take their shape according to the size of the cerebral organs . These structural idiosyncrasies, and the psychological ones that are derived from them, are maintained during the rest of life once the growth of the brain has ended.

6. The surface of the skull reveals the mind

Probably this is the most famous principle of phrenology : given that the development of the organs (and therefore of the faculties) influences the shape of the skull, the analysis of its surface allows to determine the personality and the rest of mental features of a person.

Gall and most phrenologists examined the skull with their fingers and palms to detect peculiarities, such as cracks or overdeveloped regions. They also used tape measures and, occasionally, a special calibrator that was called the "craneometer".

Phrenological organs and mental faculties

Gall proposed 27 faculties associated with brain organs concrete. Although its proposal is the best known in this field, there was never a true consensus among phrenologists regarding the number and characteristics of these regions.

1. Propagation impulse (reproductive)
2. Parental love
3. Friendly attachment and fidelity
4. Value and self-protection
5. Murder and carnivorism
6. Astucia
7. Theft and sense of ownership
8. Pride, arrogance and love for authority
9. Ambition and vanity
10. Prudence
11. Fitness for learning and education
12. Sense of location
13. Memory of people
14. Verb sense and memory
15. Language ability, talent for words
16. Preference for color
17. Sense for sounds and musical talent
18. Numerical and temporal sense
19. Mechanical fitness
20. Comparative sharpness
21. Metaphysical acuity
22. Ingenuity, sense of causality and inference
23. Poetic talent
24. Benevolence, compassion and moral sense
25. Mimicry, ability to imitate
26. Theosophy, religious feeling
27. Perseverance and firmness

Phrenology today

Although their methods were erroneous, some of Gall's claims have been confirmed over time and scientific progress. Thus, it is known that effectively there are brain structures relevant to certain functions , and that some of them develop with the use, as it happens with the hippocampus, implied in the memory.

However, phrenological approaches were very reductionist and rigid compared to what is known at present about the distribution of brain activity around regions and pathways. Likewise, the "organs" identified by Gall do not correspond to the faculties to which he associated them .

The exception is the region to which he attributed the faculty for language and verbal memory, which is located near the areas of Broca and Wernicke. These structures, located in the frontal and temporal lobes respectively, have been related to the understanding and production of language.

The contributions of phrenology and other localizationist positions on the cerebral faculties have lost relevance nowadays, but have allowed the extension of scientific knowledge. They are especially known the brain areas described by Korbinian Brodmann , which can be considered a more serious version of Gall's proposal.