Shave and a haircut

Today, I am debunking one of my biggest pet peeve old wive’s tales: that shaving makes hair grow back thicker / darker / etc..

It is imperative to understand some basic biology about hair in order to appreciate the silliness of this belief.

  • Hair grows from follicles, which are below the skin. Follicles vary in size, they don’t last forever, and are governed by hormones, both good and bad (see any male with a bald spot).
  • Your follicles grow hairs based on your own unique physiology – genetics, hormones, age, etc.. Illness, disease, diet, and habits like smoking  affect hair growth as well.
  • The hair that you can see, that which is above the skin, is dead. If it weren’t dead, getting a haircut would hurt. Living parts of your body have blood supplies and nerves. Hair (beyond the skin) does not. Formation and growth happens below the skin, in the follicle. (Fingernails are similar – you trim the dead parts.)
  • Follicles go through several phases, each lasting various amount of time from weeks to years – growth, transitional, resting. Each individual follicle has its own schedule, which is independent of neighboring follicles; this is a good thing, or else we’d all have random spots on our heads without hair, or half-eyebrows… When a follicle re-enters the growth phase, a new hair pushes out the old. We lose hairs all the time, as we are growing new ones.
  • Cutting dead hair does not affect the growing part (the follicle) any more than cutting your fingernails affects the growing part of the nail (the bed).
  • Pulling hair out by the root does, however, affect the follicle – it will damage it and over time the follicle will die.

(continued below this nifty graphic that I didn’t make)

Ok, so what about all the people who insist that they shaved something and the hair grew back coarser, darker, etc.?

A few more points to keep in mind:

  • When a follicle is growing a brand-new hair from scratch, the first few bits are narrow – that is, the hair is thinner and tapered at the end. Light reflects differently on a thinner hair than a thicker hair, and it will appear lighter in color when it is thinly tapered. The tapered end is also soft and flexible.
  • It is the size of the follicle that determines how thick your hair is. Cutting off hair does not make the follicle larger.
  • Most people begin shaving when they are relatively young. Their hair follicles are still developing, still getting the hang of making hair – so logically, as the person matures they will have thicker, darker hairs because their follicles are getting better at making hair, and most people’s hair gets darker as they get older (until it begins to go grey, of course).

Regarding the cutting / shaving itself:

  • When you cut a hair off at skin level (shave), you are removing the tapered end and exposing the full diameter of a mature hair. Light will reflect differently over this wide, mature hair than it did from the new, thinly tapered end.
  • Shaving usually cuts the hairs at a slight angle, which reveals a wider profile of each individual hair – thus adding to the illusion of thicker hair. Add in the contrast of dark stubble against light skin and the effect is magnified.
  • The wide, flat, cut end of a hair will also feel thick and sharp – because it is! Shaving is like cutting a tree; the trunk is wide and flat – but the tip of a new branch is slender and flexible. But cutting off the hair did not MAKE it thicker, the hair is thicker because the follicle is growing it that way, regardless of whether you cut it or not.
  • Shaving cuts off a whole bunch of hairs at once, revealing a whole bunch of wide, flat, cut ends. Because you have just leveled the playing field, so to speak, you are seeing and feeling a lot of hairs in the active growth phase and  stubble appears to grow quicker / thicker than before shaving. Before shaving, your individual hairs are each in their own growth cycle and don’t all fall out at once, so the growth is staggered. You don’t notice all of your hair growing at the same rate because it doesn’t – but when you create a field of stubble you are much more aware of the fact that some 85% of your follicles are in an active growing phase at any given time.
  • When you shave, you are able to observe up-close just how quickly hair grows – up to 1/2″ a month!. This is not nearly as noticable on longer hair.

Still with me?

When you pluck out a hair, you are re-setting the growth cycle of the follicle. It has to start over, and it may take awhile to do so. It also takes some time for the new hair to reach the surface of your skin and be visible – weeks, usually. And this new hair will be soft, fine, and flexible at first – because it does not yet have a blunt, cut end. This is the appeal of waxing – “slower” regrowth and softer hairs when they do show up. Plus, as I mentioned earlier, pulling hairs out by the roots damages the follicles so less hair will grow over time.

Ok, I’m sure some of you are still adamant that shaving makes your hair grow in thicker and darker. I want to point out a couple of if/then situations that might help.

  1. If this were true, then every man who shaves would end up with black stubble the size of pencil lead. My blond son might actually prefer that…
  2. If this were true, then all a person would need to do to get thicker hair would be to shave it. Millions of people with thinning hair wish this were true.


About wonkydonkey

You want random? You got it. Mostly knitting and gardening, with some home improvements, pets, baking, family, and the occasional bad joke thrown in for good measure.
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