In 1961, an endocrinologist named Dr David Ferriman and a graduate student published a study on the “clinical assessment of body hair growth in women”. More specifically, they were interested in terminal hairs (ones that are coarser, darker and at least 0.5cm/0.2 inches in length) rather than the fine vellus hairs.
The men looked at 11 body areas on women, rating the hair from zero (no hairs) to four (extensive hairs). The Ferriman-Gallwey scale was born. Most women who live with facial hair don’t refer to the Ferriman-Gallwey scale before deciding they have a problem. via: theguardian