Posted 12 October 2013 - 01:40 PM
It's more complicated than that. There is more than one gene on more than one chromosome that contributes, and how the genes contribute can depend on imprinting, which can be different on mother's and father's side.
Some of the genes involved are X-linked, which makes it statistically more likely for you to lose your hair if your maternal grandfather did, but there are a lot of other factors.
Edit: Aha, here we go, from an actual research article in a peer-reviewed publication, "Adjusting for age, men whose fathers had hair loss were 2.5 times as likely to have had some level of hair loss compared to men whose fathers had no hair loss (95% CI: 1.3–4.9)." - L. Peuvrel et al., Dermatology 2004;209:33–39
But again, this points to there being other factors, and even if you have genetic predisposition to hair loss, there are things you can do about it.
Now, I have two grandfathers and a father who have all gone bald early. So I was not the least bit surprised when my hair started rapidly receding at 20. But I never really had any objections to that, either.