Adolphe Quetelet (1796-1874)
Adolphe Quetelet was the first scientist to apply statistical methods to humans in a systematic way. Quetelet had studied astronomy and mathematics in France, and learned how French astronomers used probability to make their measurements of star positions more accurate. He reasoned that it should also be possible to apply these techniques to the measurement of human features and so created a new scientific discipline, which he called ‘social mechanics’.
He created the concept of the ‘average man’, who would exhibit the average features of all individuals. Quetelet used these methods to define what should count as normal physical and mental features, believing that comparing the features of individuals against this ‘average man’ would allow scientists to detect the underlying mechanisms which determine normal and abnormal features.
In 1835 Quetelet published a description of his new science under the title A treatise on man and the development of his faculties. The body mass index, which classifies people's weight as normal or abnormal, has its roots in Quetelet’s work.