male pattern baldness = thinning?

[hans]

Do all individual hairs that encounter the onslaught of DHT and male pattern baldness neccessarily have to go through phases of miniaturization? From noticing my hair and others who are balding (non-diffusers), it seems like the hairs on the temples just go from full-girth hairs to non-existence. And as you go to the back of the head it seems like it does take a while (more miniaturization stages) before it becomes completely bald. This brings me to another question... why is the hairline so damn fragile?! :!:

 

[The Gardener]

That is a VERY good question.

My rationalization has always been that the "DHT-sensitivity" switch in hairs is not a simple "on/off" switch. There are various degrees to which a hair can become sensitive to the onslaught of DHT, and various speeds at which this switch can change as we age.

It seems the temple hair seems to go from zero to 6, 7, or 8 very very quickly. Whereas, the vertex hair seems to hang around 3 or 4 for a while, before a small bald spot of hair runs up to 9... this being the case in those who suffer from vertex thinning.

Then, there are those folks whose entire hair may switch to a 2 or 3 as they age, their hair thins a bit, perhaps some temple creeping, but they manage to keep most of it until their death.

What regulates the switches? Genetics, I believe.