Does maturing hairlines happen because of a males testosterone?

I don’t know for sure but I suspect that you are correct. We know that females generally do not get the receded mature ‘male hairlines’ that men do. Could this be caused by genes related to our sex alone or is it that two X chromosomes with the high estrogen levels in females protected against the mature hairlines. No one has been able to study this. These hairs in the zone between the juvenile and mature hairline certainly have an ingrained number of hair cycles which then produce ‘apoptosis’ (cell death) of these hair cells possibly triggered by testosterne,