MYTH. Hair growth is determined by genetics. Shaving, cutting, or trimming it has no effect on the rate, strength or thickness of the new hair growth. Hair grows from follicles underneath the scalp and activities on the scalp level have no effect on the hair developing in the follicle.
Sources:
•https://www.pleasestopmyhairloss.com/hair-loss-myths-2/
•https://www.aderans.com.sg/understandinghair-loss3.html
•https://www.babycenter.com/404_is-it-true-that-shaving-a-babys-head-or-cutting-his-hair-ver_10303163.bc
