This regular distribution was found to apply to a number of other phenomena and so the phrase was changed to ‘standard distribution’ (about a mean). The idea was further refined in the 1890s by the English mathematician Karl Pearson (1857–1936), who introduced the term ‘normal distribution curve’, what became known as the bell(-shaped) curve. And this was, perhaps, the most influential idea of all, at least at that time, because the bell-shaped curve was used by Quetelet to produce what he called l’homme moyen, the average man.
