DS1 was always so quiet and calm. He would just sit and line up his trains neatly and push them back and forth watching the wheels going round. His always enjoyed sitting and reading as well. He would have been happy to stay home all the time. It wasn't until after he started school some of his friends went to Beaver Scouts and he wanted to go too. Then they sent Judo flyers home in their school bags and he tried that out. DS2 has always loved being out and doing things and simply can not be still. Even at night his fidgetting right up until he passes out LOL He does Judo 2 nights a week, and Karate, he wants to join Beavers when his 6 and is starting football a week on Saturday. And DS3 is a homebody, his a monkey, but a real mix of both his brothers and will sit playing with little figures for ages. The minute his through the door from pre-school his stripping off and asking for his PJs and wont leave the house again unless he has to. He even asks to leave his grandparents after an hour just because he wants to go home and get comfy LOL
I think its just a case of all children being different. I don't believe any gender is worse than the other, or more hyper than the other, or calmer or better behaved.