This study aims to test the hypothesis that shaving hair causes it to grow back thicker. It will involve 150 volunteers divided into two age groups. Volunteers will be randomly assigned to shave their arms and legs once, shave twice, or not shave at all. Hair thickness will be measured before and after using cluster samples. Blocking volunteers by age controls for natural differences in hair growth. The results will show if shaving leads to higher hair concentration when it regrows. Possible errors include volunteers not properly following the shaving treatment.