finger in archaeoastronomy Before the advent of GPS and compass, early humans used index finger for pointing direction of objects with the help of stellar objects during night time. Gestures in art As an artistic convention, the index finger pointing at the viewer is in the form of a command or summons. Two famous examples of this are recruiting posters used during World War I by the United Kingdom and the United States. The index finger pointing up is a sign of teaching authority. This is shown in the depiction of Plato in the School of Athens by Raphael. See also Digit ratio, comparative lengths of the index finger and ring finger and androgen levels in utero Extensor indicis muscle Fingering (disambiguation) Index (typography) References External links Gestures Fingers