What age do boys start puberty?

[hev3sofar]

Just wondering what the first signs of puberty are and what age it generally starts with boys? My 9yo has def changed shape lately (shoulders are broader judging by the way his tops dont fit!) he suddenly sleeps and has some anger issues going on, just wondering if this could all be hormone related? Any ideas?

My DS2 developed pubic hair by 10.. and his voice broke by 11 so I would imagine it's not that unusual to start around 9.. there is massive variation. His brother on the other hand was high pitched until he was 13/14 but had hideous anger issues from about 11 (he's 19 now and quite nice again )

Sounds quite possible that he is getting a testosterone surge !