The Scientist: Dr. Marc Avram is a New York-based dermatologist who specializes in hair transplantation and is a professor of dermatology at The Weill-Cornell Medical School.The Answer: First, plucking is usually not permanent. When you pluck a hair, you remove the hair shaft, which is the part of the hair follicle you can see. The hair shaft comes out from its base just under the surface of the skin, while the matrix underneath, which is the mechanism for growing more, remains.That said, it is possible to over-tweeze. If you spend years and years plucking the same hair, it can cause inflammation, which creates scar tissue. The scar tissue acts like cement, covering the matrix so the follicle can’t grow anymore. Bye, bye, brow.Shaving is more superficial than plucking. You’re cutting the hair shaft flush with your skin. When it grows back, the hair may seem thicker, but it’s not, we swear. The shorter new growth only feels thicker because it’s straight—and sticking straight out. You know how it feels when you run your hand over a guy’s fresh buzz cut? It’s just like when the hair on your legs grows back after shaving (except that on you it’s not so cute).MORE ON HAIR REMOVAL FROM YOUBEAUTY:How Hair GrowsGetting Rid of Hair at HomePro Tips for Brow Shaping