Phrenology was a pseudoscience that argued that The shape of the skull gave information about mental faculties and traits of people. This movement was popularized in the 18th century by the doctor Franz Gall and had a large number of followers, 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 Gall’s disciples had. Finally, we will talk about the legacy of phrenology in modern neuroanatomy.
Phrenological hypotheses did not arise in a vacuum, but were derived from previously existing conceptions. In particular, during the 18th century, physiognomy, which proposed that people’s physical appearance could be used as a basis for analyzing their psychology, enjoyed some popularity, and Charles Bonnet influenced cerebral localizationism.
German physician Franz Joseph Gall (1758-1828) He began lecturing on phrenology in 1796. It was his collaborator Johann Gaspar Spurzheim, also a key figure, who spread the word “phrenology,” which Gall disavowed since he saw himself primarily as a physiologist and neuroanatomist.
Like mesmerism, phrenology spread as a probable scientific truth among the lower and middle classes of 18th century Europe, very open to advances in different fields due to the influence of the French Revolution and the Enlightenment. Edinburgh became the center of phrenology and the first phrenological society was founded there.
By the 1840s, just 40 years after its emergence, the hypotheses of phrenology 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 times, especially as a tool of racial domination.
Basic postulates of Franz Joseph Gall
In 1819 Gall published his key work: “Anatomy and physiology of the nervous system in general, and of 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 also not new in Gall’s time, enjoys great popularity. This approach was opposed to the conception of the mind as a manifestation of the soul, which was more widespread in the 18th century than today.
2. The mind is made up 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, such as 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 mental faculties are different and unique, they must necessarily be located in “organs” separate from the brain. This postulate makes phrenology a antecedent of localization theories on the functions of the central nervous system.
The relative size of each organ compared to the rest of the brain can be taken as a sign of the development of a particular faculty, according to phrenology. Likewise, an organ can be larger in one of the cerebral hemispheres than in the other.
5. Organs determine the shape of the skull
Gall stated that during childhood development The bones of the skull take their shape according to the size of the brain organs These structural idiosyncrasies, and the psychological ones that derive from them, are maintained for the rest of life once brain growth has ended.
6. The surface of the skull reveals the mind
This is probably the most famous principle of phrenology: since the development of the organs (and therefore the faculties) influences the shape of the skull, the analysis of its surface allows us to determine the personality and the rest of the mental traits of a person.
Gall and most phrenologists examined the skull with their fingers and palms to detect peculiarities, such as indentations or overdeveloped regions. They also used measuring tapes and, occasionally, a special caliper called a “craniometer.”
Phrenological organs and mental faculties
Gall proposed 27 faculties associated with brain organs concrete. Although his proposal is the best known in this field, there has never been a true consensus among phrenologists regarding the number and characteristics of these regions.
Phrenology today
Although his methods were flawed, some of Gall’s claims have been confirmed with the passage of time and scientific progress. Thus, it is known that indeed there are brain structures relevant to certain functions and that some of them develop with use, as happens with the hippocampus, involved in memory.
However, phrenological approaches were very reductionist and rigid compared to what is currently known about the distribution of brain activity around regions and pathways. In addition, The “organs” identified by Gall do not correspond to the faculties with which he associated them
The exception is the region to which he attributed the faculty for language and verbal memory, which is located near Broca’s and Wernicke’s areas. These structures, located in the frontal and temporal lobes respectively, have been related to the comprehension and production of language.
The contributions of phrenology and other localizationist positions on brain faculties have lost relevance today, but they 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.
