Why do people go bald?

I should make it plain from the outset that I don't really understand why people go bald. I'd probably be very rich if I understood that! Baldness is what is described as a sex limited condition rather than a sex linked condition, which means it tends to affect one sex more than the other. In this case it's obvious: it affects males more than females. But it's not a straight forward inheritance of a gene on the Y-chromosome, for example, that leads to baldness. The genetics and inheritance patterns are more complex than that, otherwise people would have been able to follow these inheritance patterns through families and understand more about the genetics of baldness. So we're not there yet, but we have some useful information.