Phrenology or Craniology is a pseudoscience that involves the measurement of bumps on the skull to predict mental traits. It is based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions or modules. It was said that the brain was composed of different muscles, so those that were used more often were bigger, resulting in the different skull shapes. This led to the reasoning behind why everyone had bumps on the skull in different locations. The brain "muscles" not being used as frequently remained small and were therefore not present on the exterior of the skull. Although both of those ideas have a basis in reality, phrenology generalizes beyond empirical knowledge in a way that departs from science. The central phrenological notion that measuring the contour of the skull can predict personality traits is discredited by empirical research. Developed by German physician Franz Joseph Gall in 1796, the discipline was influential in the 19th century, especially from about 1810 until 1840. The principal British centre for phrenology was Edinburgh, where the Edinburgh Phrenological Society was established in 1820.
Phrenological skull, European, 19th century. Wellcome Collection, London
The Phrenologist, a sketch by A.S. Hartrick, 1895
George Combe
1848 edition of American Phrenological Journal published by Fowlers & Wells, New York
Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claims; reliance on confirmation bias rather than rigorous attempts at refutation; lack of openness to evaluation by other experts; absence of systematic practices when developing hypotheses; and continued adherence long after the pseudoscientific hypotheses have been experimentally discredited. It is not the same as junk science.
A typical 19th-century phrenology chart: During the 1820s, phrenologists claimed the mind was located in areas of the brain, and were attacked for doubting that mind came from the nonmaterial soul. Their idea of reading "bumps" in the skull to predict personality traits was later discredited. Phrenology was first termed a pseudoscience in 1843 and continues to be considered so.
The astrological signs of the zodiac
Homeopathic preparation Rhus toxicodendron, derived from poison ivy