"Is there an art, to read the mind's construction in the face?" asked Shakespeare, rhetorically. A discredited 19th-century science, phrenology, derided as "bumpology", is now viewed as one of the more ludicrous attempts to answer this. In the late 18th century, Swiss priest Johann Casper Lavater formulated his "physiognomy", with axioms like "the more the chin, the more the man" and "as are the lips so are the character".
Then Viennese physician Franz-Josef Gall (1858-1828) "noticed" that people with large eyes had good memories and codified correspondences between shape of head and intellect in mental patients. Gall believed that external bumps on the skull reflected internal "organs" on the brain surface. These 27 organs were specialised, with emotions such as wonder and veneration, actions such as murder and larceny, and attitudes such as "amativeness" and benevolence developing and declining separately, according to usage.
Interpret the bumps and there you are - the persona was revealed.
Followers, including Johann Spurzheim (1776-1832) in America and George Combe (1788-1858) in Britain, sold hundreds of thousands of books identifying more organs such as those for wit, tune, colouring and weight.
In 1815 these ideas were lumped together as phrenology (science of the mind). Gall and company dismissed any contrary evidence, ignoring the fact that since dissection was largely practised on the mad and bad their sample was skewed to the morbid.
By the late 19th century, psychology had moved on to environment and infant development, while phrenology became a parlour game, with charlatans "reading" heads for money and offering to massage away unwanted formations.
Its most sinister legacy was the work of Cesare Lombroso (1835-1909), who suggested identifying potentially dangerous criminals by the shape of their skulls, so that they could be "treated" before they transgressed.
Yet Gall was just ahead (so to speak) of his time. In localising perceptions and faculties in the brain, he anticipated today's cutting-edge research, explored in magnetic resonance imaging (MRI) of expanding and contracting blood vessels within the brain, which minutely details brain function even to melody and colour. As they say: "you ought to have your head examined."