Not just a combination of basic nature of personality, immediate family, friends attitude towards him, behaviour learned from the environment and life experiences but a person's general health contributes alot towards his approach towards life & how he handles day to day situations.
Excellent health (physical) can contribute towards his success in life and make him a winner but with poor health at any point, he will only turn out to be a failure.
So it depends on the 'level' of a person's general health. Better the level of his health on a scale of 1 - 10, the better he would be able to handle his life and his attitude towards life's situations and people he comes across.