Phrenology (Greek: Mind, Knowledge) was the pseudoscientific practice of measuring and characterizing the surface features of the skull and assigning function to specific locations in the brain by virtue of "organs." It was considered and promoted as scientific by its practitioners.
Phrenology has been largely discredited, but it is still promoted as a science by some organizations in Europe and North America.


Phrenology emerged from cranioscopy as detailed in the history. As such it emphasized using measuring devices to arrive at precise measurements of the skulls surface topographic characteristics and volume.
It claimed as operating principles:
  1. The Brain is the organ of the mind.
  2. The skull takes shape from the surface of the brain.(Wyhe, n.d.)
  3. The surface features of the skull are meaningful - i.e. diagnostically and clinically indicative.
  4. Skull elevations and features on the head are indicative of the location of specific "organs" or "faculties."
  5. The location of "organs" of the mind as indicated by the topographical features of the skull and specific features corresponded to specific personality characteristics and behavioural tendencies.
  6. The areas of the brain indicated by skull surface elevations features were proportional in size to someone's personality tendencies and proclivities; the larger the elevation or depression in the given area, the greater the tendency or lack of it.
  7. Phrenology is scientific.


1. Clinical Assessment and Practice

Phrenology employed a precise measurement tool called the craniometer. This device allowed for the skull to be mapped mathematically and a topographical surface map to be developed indicating the position and magnitude of the elevations and depressions in the skull. From the mapping of thousands of skulls, phrenologists developed typical phrenological skull profiles and codified into them to be referenced during evaluation practice. The phrenologist could also use a standard measuring tape to obtain measurements.
Equipped with the appropriate reference material, a trained phrenologist would begin the clinical evaluation by running their hands and fingers over the participants head (Parsinen, 1974, p.2). The phrenologist would examine the individuals general skull shape, their skull surface elevations and depressions and would compare his observations and measurements to the established reference values.
From this clinical evaluation the phrenologist would be able to conclude information about the participants current character and temperament and future behavioural tendencies.

2. Gall's Skull

This skull is a typical example of a phrenology skull. Note that it has the locations of different organs and associated faculties mapped onto the surface. Each of the separate organs and associated faculties are inscribed by location and written in Latin.
Specifically, this is said to be the skull used by Gall.
1848 edition of American Phrenological Journal published by Fowlers & Wells, New York City.
This is the skull said to be used and created by Franz Joseph Gall depicting the organs and faculties.


1. Franz Joseph Gall - (1758-1828) - ORGANOLOGY, CRANIOSCOPY

Phrenology was established by Franz Joseph Gall in 1796. Gall was a German anatomist. Phrenology developed from two earlier disciplines developed by Gall: organology and cranioscopy. Organology was an attempt to study isolated mental functions by determining the location of the specific "organ" in the brain as indicated by skull surface bumps. Cranioscopy measured the spatial characteristics of the skull using external measurement devices to determine the relative development of the "organs" in the brain. Phrenology emerged from Organology and Cranioscopy, and its purpose was to study the bumps and ridges on the surface of the skull to: determine relative development of brain "organs," characterize and correlate personality and skills with "organ" development according to bump measurements, and to indicate intellectual function and emotional propensities of a person using physical bump and skull measurements.
Gall published The Anatomy and Physiology of the Nervous System in General, and of the Brain in Particular, with Observations upon the possibility of ascertaining the several Intellectual and Moral Dispositions of Man and Animal, by the configuration of their Heads in 1819. Thispublication outlined the following fundamental tenets of cranioscopy (Lyons, 2009):
  • The brain is the minds organ
  • The brain is a composite of different organs, each of which is functionally discrete
  • Brain are topographically mapped and have a specific location
  • Organ size reflects organ power and strength
  • Skull ossification occurs during infancy, and the resulting skull characteristics can be used diagnostically to determine the states of mental character.
Additionally, Gall's book established and classified the organs as follows:

The Anatomy and Physiology of the Nervous System in General, and of the Brain in Particular, with Observations upon the possibility of ascertaining the several Intellectual and Moral Dispositions of Man and Animal, by the configuration of their Heads
1. Impulse to propagation
2. Tenderness for the offspring, or parental love
3. Friendly attachment or fidelity
4. Valour, self-defense
5. Murder, carnivorousness
6. Sense of cunning
7. Larceny, sense of property
8. Pride, arrogance, love of authority
9. Ambition and vanity
10. Circumspection
11. Aptness to receive an education, or the memoria realis
12. Sense of locality
13. Recollection of persons
14. Faculty for words, verbal memory
15. Faculty of language
16. Disposition for colouring, and the delighting in colours
17. Sense for sounds, musical talent
18. Arithmetic, counting, time
19. Mechanical skill
20. Comparative perspicuity, sagacity
21. Metaphysical perspicuity
22. Wit, causality, sense of inference
23. Poetic talent
24. Good-nature, compassion, moral sense
25. Mimic
26. Theosophy, sense of God and religion
27. Perseverance, firmness
*Gall held that organs 1-19 were shared by all animals, and organs 20-27 were human specific.
Gall held that each of these organs had a specific location within the brain and that the surface of the skull reflected the internal organ organization within the brain, and therefore that each of these organs could be diagnostically evaluated by examining the surface features of the skull at the location on the skull corresponding to that organ location.
Gall arrived at his conclusions through experimentation and observation. From his experiments he concluded that a relationship exists between personality characteristics he called "faculties" and specific "organs" he identified in the brain.

2. Johann Gaspar Spurzheim (1776-1832)

Johann Gaspar Spurzheim was a German physician and was a student of Gall. Spurzheim was a strong advocate of the original cranioscopy established and developed by Gall, but developed it further by increasing the number of "organs" and their assigned locations on the skull, creating a hierarchical system from the generalized cranioscopy of Gall, and renaming the resulting product phrenology.

Spurzheim published Physiognomical System in two editions in 1815. In this work he increased the number of organs proposed in Gall's original system from twenty-seven to thirty-three.

Physiognomical System
1. Organ of amativeness - physical love
2. Philoprogenitiveness - love of offspring, children
3. Inhabitivness
4. Adhesiveness
5. Combativeness
6. Destructiveness
7. Constructiveness
8. Covetiveness
9. Secretiveness
10. Self-love
11. Approbation or love of approbation
12. Cautiousness
13. Benevolence
14. Veneration
15. Hope
16. Ideality
17. Conscientiousness
18. Firmness
19. Individuality
20. Form
21. Size
22. Weight / Momenta
23. Colour
24. Space / Locality
25. Order
26. Time
27. Number
28. Tune
29. Language
30. Comparison
31. Causality
32. Wit
33. Imitation
Spurzheim created a hierarchical system from the "base" organ elements created by Gall. In doing so, Spurzheim structurally codified and consolidated the organs and their functions thereby going beyond Gall's system of cranioscopy.

He popularized phrenology and its methods and values in England and France and America (Staum, 2003). He did this successfully by using visual aides - images and busts of skulls with the locations of the organs and assigned functions mapped on the skull for everyone to see. This made the Phrenological system an immediately tangible and available tool that everyone could access and use in their daily lives.

3. George Combe (1788-1858)

George Combe was a phrenology writer and a lawyer by profession. Combe lived in England and was the founder of the Edinburgh Phrenological Society which he founded in 1820. This organization had many scientists with medical backgrounds claiming membership (McGrew, 1985). His book The Constitution of Man Considered in Relation to External Objects was published in 1828.
In his book Combe put forth many claims, some of which are taken as givens by modern scientific researchers, including that the human brain and therefore mind is subject to the same natural laws as external matter and that human behaviour could be explained in terms of the brains activity, not through religious or philosophical frameworks.

Combe published A System of Phrenology (1851) in which he promoted phrenology as a science. In this work he attempted to adapt phrenology to the Victorian values of the time (Parssinen, p.3). Additionally, like Spurzheim before him, Combe developed phrenology by increasing the number of organs and re-classifying the organs into broad categories:
A System of Phrenology
1. Propensities
  1. Adhesiveness
  2. Alimentiveness
  3. Amativeness
  4. Acquisitiveness
  5. Causality
  6. Cautiousness
  7. Combativeness
  8. Concentrativeness
  9. Constructiveness
12.Love of life
2. Sentiments
Lower Sentiments (Common to man and animal)
  1. Cautiousness
  2. Love of Approbation
  3. Self-esteem
Superior Sentiments (Produces emotion, not present in other animals)
  1. Benevolence
  2. Conscientiousness
  3. Firmness
  4. Hope
  5. Ideality
  6. Imitation
  7. Veneration
  8. Wit or Mirthfulness
  9. Wonder
3. Intellectual Faculties (Used to detect the external world based on its physical qualities)
  1. Coloring
  2. Eventuality
  3. Form
  4. Hearing
  5. Individuality
  6. Language
  7. Locality
  8. Number
  9. Order
4. Reflecting Faculties (Act in the service of the other faculties listed)
  1. Causality
  2. Comparison
Combe was a lawyer and was interested in phrenology from a legal and social perspective. He was concerned with criminal behaviour and believed that phrenology could be used as an effective tool in the humane diagnosis and reforming of criminals. As he believed that the brain is the organ of the mind, Combe advocated treating criminality as a brain condition and the reorganization of the brain organs as the means for rehabilitation.


1. Bernard Hollander (1864-1934) & Paul Bouts (1900-1999)

English psychiatrist Bernard Hollander and Belgian Roman Catholic Priest Paul Bouts were the primary developers and promoters of phrenology as a science in the twentieth century.
Hollander published The Mental Function of the Brain (1901) and Scientific Phrenology (1902). In these works, Hollander presented a skull measurement method and a procedure for comparing individual measurements with statistical averages based on previously collected data (Hollander, 1891).

Bouts published Psychognomie(1931) and Les Grandioses Destinées individuelle et humaine dans la lumière de la Caractérologie et de l'Evolution cérébro-cranienne (1960). Bouts sought to merge phrenology with the tenets of paleoanthropology - the study of ancient human beings and human evolution. Specifically, Bouts held the view that evolution had the aim of perfection of man, and this perfection and the degrees of evolution in each person could be measured by the features of the skull. Consistent with this view, Bouts held that savages - non-Europeans - and criminals were less advanced and evolved and that this could be confirmed by following the principles and methods of phrenology. Currently, a Dutch organization called Per Pulchritudinem in Pulchritudine (PPP) continues to promote the works of Bout.

C.W. Le Grand was the President of the British Phrenological Society from 1958-60 and was upset that many people had unfairly rejected it Le Grand claimed that phrenology
was rejected without fair examination of its tenets because of a vast misunderstanding about and mischaracterization of, Phrenological principles and methods (Le Grand, n.d.). Others, including the PPP promoting the works of Bouts advance the same claim today in defence of phrenology.


1. Criminals and Prisoners

Proponents of phrenology claimed that it could be used to identify and diagnose persons with criminal tendencies.
Phrenology was used on criminals and prisoners as a treatment paradigm. Phrenology held that the organs of the brain could be reorganized and that rehabilitation would occur from organizing a disorganized brain through strict daily living conditions, including hard work and moral instruction. It was thought that this reorganization would eliminate criminality and develop other organs and compensatory faculties in its place.
Some criminals, however, specifically those high in intelligence and aggressiveness would never be released.

2. Psychological Conditions

Persons with mental disabilities or psychologically impairing conditions were often institutionalized in sub-standard and inhumane living conditions. Phrenology advocated diagnosing these persons, determining their abilities, and placing them in skill-appropriate jobs. It is also claimed that phrenology made treating the mentally ill more humane.


1. Class Superiority

In practice phrenology was used to maintain the status of the ruling upper-class European populations over the lower-classes in Continental Europe. By ranking the races according to organ development as indicated by measuring bumps on the skull, phrenologists were able to classify the races by superiority and inferiority and to state what class or race of persons had undesirable tendencies and proclivities. This coupled with the claimed predictive power of phrenology to forecast behaviour based on surface skull features allowed phrenology to be used for social discrimination that led to the unfortunate victimization of persons not fitting the social, intellectual or phrenological profile of the ruling class.

2. Scientific Racism

1. Samuel George Morton (1799-1851)

Samuel George Morton was an American anthropologist and physician. His work focused on collecting skulls, measuring them, and correlating skull measurement data - i.e. cranial capacity - with race. He concluded that larger skulls indicated larger brains and higher intelligence compared to small skulls indicating lower intelligence. He also concluded in his book Crania Americana that Caucasians, of which he was one, had the largest brains with Negros the smallest (Thomas, 2001).

2. Francis Galton (1822-1911)

Francis Galton was the developer of eugenics. He advocated using phrenology to classify skulls of different races according to their craniometric characteristics, including size and shape. Galton was a cousin of Charles Darwin and he established exhibits showing the skeletons of European whites next to African skeletons and non-human primate skeletons, in that order. This exhibit and the ideas underlying it were used as the framework to justify racism on scientific grounds.

3. American Slavery

Phrenology was used in the Americas as justification for slavery. Phrenology was popular among slavery proponents who argued that slaves were less evolved, less civilized, and in need of slavery to contain their savage and criminal tendencies.

4. Civil Antagonism - Rwanda

The Belgian colonial government in Rwanda in the 1930's used phrenology as a framework for social policy development, and as a means of justifying the assumed superiority of one group, the ruling Tutsi class over another group, the subjugated Hutus (Lisa, n.d.).
This use of phrenology contributed to repressive social policies against minority class Hutus and would lead to the violence and genocide in the 1990's .


Phrenology was popular and enjoyed mass appeal because its ideas and methods were demonstrable, easily accessible to the masses and of perceived immediate social utility by governing powers. As one source notes, the popularity of phrenology was due in partto the lack of rigid modern scientific methodology at the time, with acceptable standards of evaluation and analysis were still in development.

1. Geographic Distribution

Phrenology enjoyed widespread success throughout Germany, Belgium, the United Kingdom, Canada, the United States, Brazil, the African Colonial Territories and limited popularity in France and Ireland. Sources indicate that people paid for consultations with phrenologists frequently and solicited their council on many issues (McCandless, 1992).
Opposition to phrenology in France prevented it from becoming highly fashionable and it enjoyed only minor success in France. It was from France that phrenology was first attacked as being a pseudoscience.


Phrenology was taken seriously as a form of popular psychology in the 1840's but had largely been discredited as a bona fide science in 1843. It took time for the facts and criticisms of phrenology to catch up to the widespread public belief that phrenology was scientific.
One of the first to criticise phrenology and to explicitly call it a pseudoscience was Francois Magendie in 1843 who remarked that phrenology was "a pseudo-science of the present day" (Fodor, 1983). Phrenology has been criticised as a pseudoscience on the following grounds.

1. Lack of Internal Consistency, Structure, Uniformity

Phrenology was criticized because of internal disagreement among practitioners on the fundamentals of the system. For example, the number of organs and their arrangement and assigned locations on the skull were not universally agreed to by all practitioners, and this had implications not only for the coherency of the system of phrenology as a whole, but also for subsequent consistency of conclusions reached using phrenological methods. With strong disagreement among the practitioners on organ number and location, phrenology was criticized as lacking internal consistency and structure and for lack of uniform conclusions across practitioners.

2. Confirmation Bias and Biased Interpretation

Critics claimed that phrenology sought only to confirm its own apriori tenets by ignoring, explaining away or re-interpreting contradictory evidence to fit with their hypotheses. An example of this would be the situation of examining a person who although a phrenological examination of their skull reveals they have well-developed language areas, they couldn't speak. Instead of concluding that the diagnosis or validity of method was wrong, phrenologists would conclude that other compensatory organs in the brain were somehow stopping the language faculty from working. By accounting for every possible counterfactual example, phrenology was criticised as being biased in its interpretation of evidence. It forbade nothing to happen and allowed for everything to happen.

3. Resistance to Deductive Conclusions

It was noted that phrenology was popular during a time when modern scientific practices and standards were still being developed. Within the modern paradigm, phrenology is pseudoscience because it does not have an objective, open and transparent method of deduction and hypothesis testing. Phrenology constitutes a closed-system of structured information that is not tested for counterfactual occurrences. It seeks not to establish the truth of its tenets by reference to external examples and testing, but to apply them as true by classifying people according to the tenets of phrenology, thereby apriori making all cases confirmatory within the phrenology framework regardless of factual conflict. Through biased interpretation and confirmation bias phrenology seeks to make universally categorical statements that account for all possible outcomes and their opposites, thereby isolating its principles and methods from testing and criticism.

4. Lack of Prediction Power

Phrenology lacked the ability to produce specific and testable predictions. What conclusions it did make can be best termed conjectures or nothing more than untested hypotheses. Not only did phrenology only produce summary conclusions from its activities that were in many cases verifiably wrong, but it didn't make specific predictions to hold itself to account. This failure to generate genuine predictions from theory qualifies phrenology as a pseudoscience.

5. Biological Science Challenges

Phrenology was not popular in France, and a French physiologist called Jean Pierre Flourens conducted experiments with pigeons in which he removed parts of the brain. Flourens reported that the removal of brain tissue caused either no observable effect in the animal or a behavioural effect that ran counter to phrenological predictions. This was a direct challenge to the work of Gall. Phrenology was unable to produce an answer to this challenge.

6. Falsifiability

Deduction and falsificationism explicated by Sir Carl Popper and incorporated into the scientific practice stand in stark contrast to the intuitive, inductive and pseudo-deductive practices of the phrenologist.
The phrenologist engages in an intuitive and inductive practice when examining the surface characteristics of the skull of individual persons. This phrenological evaluation depends on the individual practitioners knowledge and biases and their preference for one form of phrenology and its associated organs over another. Depending on the tradition of phrenology used, the practitioner could arrive at different conclusions. Many choices were left to the biases, intuitions and inductive calculations of the practitioner regardless of objective truth status.
Phrenology aimed to get around this criticism by referencing phrenological-mapped skulls and busts during examination. But this constitutes only a pseudo-deductive activity at best as the information mapped on the skulls and busts being referenced was selected by the creator of said skulls and busts according to their traditions. Such information, as outlined, was determined via induction alone without reference to counterfactual examples.
Therefore, despite having the appearance of a science that employs induction and deduction, phrenology employed induction and pseudo-deduction in an attempt to legitimize itself and isolate itself from criticism. But the lack of making falsifiable predictions makes it so that phrenology can not even be wrong in many cases; it makes phrenology not even bad science, or wrong science; it becomes not even a science. It therefore qualifies as pseudoscience.


Phrenology was a form of scientific practice prior to the development and widespread use of the modern scientific approach. Practice involved reading the elevations and depressions on subjects heads, comparing these values to established references and generating conclusions about the subjects dispositions, behavioural inclinations, skills and personality.
Phrenology was founded and developed in the early 1800's and enjoyed widespread popularity and use in the United Kingdom, Belgium, Germany and their associated colonies and Colonial Occupied Territories around the World.
Phrenology was applied socially with bad effects. The ideas entrenched in phrenology contributed to class segregations and, ultimately, to civil strife.
Phrenology came under attack in 1843, being explicitly called a pseudoscience and facing challenges from biological experimentation that it simply could not answer. Phrenology quickly fell out of favour in scientific circles at that time and experienced popular decline shortly thereafter. It is marginally promoted today by various groups that maintain an internet presence.

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