You take siblings as an example, but not twins, this is a little different.talking of twins...
Prince Harry is finally catching up with his slapcel brother. I wonder if any of them had medication. They actually started massive balding at similar age despite everyone saying he wouldn't go bald like his bro
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This is his genetic destiny... brutal
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TLDR: you can't escape your genetic predisposition, its just a matter of time.
Identical twins are interesting in that their baldness must occur at the same time and in general according to the same pattern. When one goes bald and the other doesn't, it begs the question of genetic theory and the question of how much the environment is involved. By environment, I don't mean what you drink, where you walk and what you breathe, I mean chronic diseases, infections, injuries, etc.