A metoposcopist is a person who practices metoposcopy. So far so good.
Metoposcopy is the art of judging a person’s character and fortune from his face, principally his forehead. This is not so strange an idea, since that part of the face is prominent and expressive. Persons with high foreheads are considered brainy; those with short ones are sometimes thought to be almost Neanderthal. The play of the muscles on the forehead in concentration or contemplation is an expressive reflection of the mind working beneath the skin.
Metoposcopy was a medieval method of assessment, together with such related techniques as chiromancy (divination using the hand) and podomancy (which is prognostication from the condition of one’s feet). The more general term that refers to the whole face is physiognomy. Metoposcopy is said to have been invented in the sixteenth century by Gerolomo Cardano, a man better known for his pioneering work in medicine and mathematics. His book, Metoposcopia Libri Tredecim, contained more than 800 woodcuts illustrating facial positions he suggested were associated with temperament and destiny.
The word comes via Late Latin from Greek and derives from the Greek word metopon, forehead.