What was Le Corbusier’s Modulor system based on?

Le Corbusier’s Modulor system is an additive proportioning scale based on a study of human proportions and the golden ratio (often denoted by the Greek letter $\varphi$).123

Developed by the Swiss architect to incorporate a "human scale" into his work, the system uses harmonic measures that set architectural elements in proportion to human stature. By applying these mathematical ratios, Le Corbusier sought to organize the dimensioning and proportioning of his architectural plans, ensuring that buildings remained in a meaningful scale with respect to the human body. He famously applied this system to projects such as the housing complex La Cité Radieuse in Marseille.2413