Men start going bald 25-30ish due to heredity and genes.
I also venture to guess that men go bald also due to frequent haircuts. All that cutting and pulling on your hair by the barber could possibly cause guys to bald??? Maybe perhaps??
I heard that wearing hats,baseball caps contribute to thinning hair also. But unfortunately some guys just start thinning their hair and receding hair line late 20's just due to genes.
On a side note, the account of Samson in the Bible. If his long hair gave him strength, then what is so bad about having long hair??? What is so wrong with long hair if it made someone robust/strong????