Not sure if this survey has been done before. But I'd be interested to see what the community's results for this would be, and if anyone has general studies of the onset of baldness in populations. Ideally with country to country comparisons.
Theory of Mine
I theorise that the onset of male pattern baldness occurs when one's level of DHT (and therefore Testosterone) is above a threshold level. Children and Women have testosterone in levels far too low to have an impact on their hair, even if they do have hair which is sensitive to DHT. When DHT exceeds a threshold (which varies over the scalp hairs in the M shape pattern and Vertex radial pattern), these hairs progressively shrink.
M shape pattern (Frontal hair loss): The hairs at the very front are the most DHT sensitive, as you go further back, the hairs become more DHT resistant.
Vertex shape pattern (Crown hair loss): The hairs at the focal point of the crown are the most DHT sensitive, as you move away from this point, the hairs become more DHT resistant.
If it were simply a case of having DHT sensitive hairs, and non-DHT sensitive hairs. Then the onset of male pattern baldness would result in *ALL* DHT sensitive hairs miniaturising at the *EXACT* same time. So we know there is varying levels of sensitivity (or vulnerability) amongst the DHT sensitive hairs.
Testosterone in males steadily increases until around somewhere around age 30-40, and then it declines (along with libido). This is why in males that are susceptible to male pattern baldness. If they haven't experienced balding by around age 40. They've essentially dodged it. And if they do experience it at this age, it'll be at a slower rate than those in their early 20's (unless they have a radical change in diet/exercise/sexual regime.) Patrick Stewart (Jean Luc Picard from Star Trek TNG) was quoted as saying that he lost all his hair in the space of a year around age 19.
The mechanism behind natural diffuse hair thinning at much older ages (50+) occurs in males and females, and I believe is something different.
Theory of Mine
I theorise that the onset of male pattern baldness occurs when one's level of DHT (and therefore Testosterone) is above a threshold level. Children and Women have testosterone in levels far too low to have an impact on their hair, even if they do have hair which is sensitive to DHT. When DHT exceeds a threshold (which varies over the scalp hairs in the M shape pattern and Vertex radial pattern), these hairs progressively shrink.
M shape pattern (Frontal hair loss): The hairs at the very front are the most DHT sensitive, as you go further back, the hairs become more DHT resistant.
Vertex shape pattern (Crown hair loss): The hairs at the focal point of the crown are the most DHT sensitive, as you move away from this point, the hairs become more DHT resistant.
If it were simply a case of having DHT sensitive hairs, and non-DHT sensitive hairs. Then the onset of male pattern baldness would result in *ALL* DHT sensitive hairs miniaturising at the *EXACT* same time. So we know there is varying levels of sensitivity (or vulnerability) amongst the DHT sensitive hairs.
Testosterone in males steadily increases until around somewhere around age 30-40, and then it declines (along with libido). This is why in males that are susceptible to male pattern baldness. If they haven't experienced balding by around age 40. They've essentially dodged it. And if they do experience it at this age, it'll be at a slower rate than those in their early 20's (unless they have a radical change in diet/exercise/sexual regime.) Patrick Stewart (Jean Luc Picard from Star Trek TNG) was quoted as saying that he lost all his hair in the space of a year around age 19.
The mechanism behind natural diffuse hair thinning at much older ages (50+) occurs in males and females, and I believe is something different.
