O2BMe - I think behaviour is partly learned (like me shouting at the kids, using the same tone of voice and words that our Mum used on us).
Some is definately genetic though.
Four years ago, DH's daughter - my step daughter - came over from Australia to stay with us. Despite the fact that DH hadn't been able to see her since she was a litle girl, she had exactly the same gait, mannerisms and temperement as DH. Its was very spooky, she even snored the same snore when alseep LOL!
What was even spookier was watching her, DH and DS. They all had the same walk, gait and mannerisms !! Despite the fact that she and DS had never even met each other before! They all had the same legs too, but then we know that's inherited
DS has definetly inherited by insane impatience too, which I clearly get from my Dad, as I react identically to him in many situations. - although of course, that aspect may well be learned behaviour?