The Cranioscopy of Franz Josef Gall
The idea of cranioscopy, now most commonly called phrenology, was invented by the renowned anatomist Franz Josef Gall in the early 1800's. Born in 1758, Gall studied medicine in Strasbourg and Vienna and his research concentrated on neuro-anatomy and craniofacial morphology (Tomlinson, 2005). As a neuro-anatomist Gall was exposed to numerous clinical cases whereby people had received head trauma that resulted in either intellectual deficits or personality changes. Gall also conducted neuro-anatomical studies directly on the brain which proved clear anatomical differences between across the cortex which be believed supported the functional differences across these same cortices. He thus identified 27 different 'faculties' in the cerebral cortex (Benjamin 2014).

It was Gall's research in cranial morphology that led him to observe that individual craniums had either indentations or bumps in certain areas. Gall's Cranioscopy was based on three assumptions drawn from his observations. Firstly, the brain is the organ of the Mind. Secondly, that the brain is divided into faculties that represent emotional, intellectual and moral capacities of an individual (Kardas 2014). Gall described each of the faculties themselves as organs and that collectively they accounted for the functions of the brain (Gall, 1835). Lastly, these areas of the brain change over time, especially during early development, and cause the cranium to change shape (Kardas 2014). Therefore, less developed faculties would result in indentation whereas bumps would represent over developed faculties. Gall's theories asserted that the mental structures he charted were largely determined by birth (Tomlinson 2005). That is, the development that takes place to form the cranio-morphology is prenatal. As such, environment and education could influence one's character but experience does not impact one's faculties.
Despite the anatomical background to phrenology the methods used to piece together the various pieces of research into a serviceable framework were less scientifically valid. Gall describes these methods:
"I assembled a number of persons at my house, drawn from the lowest classes and engaged in various occupations, such as fiacre driver, street porter and so on. I gained their confidence and induced them to speak frankly be giving them money and having wine and beer distributed to them."
(Gall, quoted in Cooter, 1984:4).
Additionally, reading Gall's description of the faculties you are often presented with a personal narrative of their discovery. When describing the discovery of the faculty of 'Verbal Memory' Gall explains that he first observed this schoolboy.
"I continued to remark that the pupils, who learned by heart with the greatest facility, were those who had large, flaring eyes"
(Gall, 1835:7)
Despite the method that Gall used to identify his so-called faculties and the fact that he did not present testable evidence for many of his claims his work did popularise the ideas that the brain produces behaviour and different parts of the brain are responsible for different cognitive functions. This made it possible for later neuro-anatomists to conduct research on the brain-behaviour relationship (Kardas, 2014). One such researcher, Pierre Flourens, designed a study to test Gall's assertions. Gall (1835) had argued that 19 of his 27 faculties applied to animals as well as human. Flourens removed tissue from animals relating to sexual behaviour and could demonstrate that this behaviour was still present (Benjamin, 2014).
Benjamin, Ludy. T. Jr. (2014) A Brief History of Modern Psychology (2nd Edition). Wiley: New Jersey
Cooter, Roger (1984) The cultural Meaning of Popular Science: Prenology and Organization of Consent in Nineteenth-Century Britain. Cambridge University Press: Cambridge
Gall, F. J (1835) On the Functions of the Brain and of Each of its Parts: with observations on the possibility of determining the instincts, propensities, and talents, or the moral and intellectual dispositions of men and animals, by the configuration of the brain and head (Translated by W. Lewis). Marsh, Capen & Lyon: Boston
Kardas, E. P. (2014) History of Psychology: The Making of a Science. Wadsworth: London.
Tomlinson, Stephen (2005) Head masters: phrenology, secular education, and nineteenth-century social thought. University of Alabama Press: Tuscaloosa