What determines the economic success of an individual?

What determines the success of an individual in terms of net worth and income? How important are the socioeconomic status of the family of origin and the place where the person grows up? Apart from that, which biological traits influence the outcome, such as intelligence quotient, social skills, health and physical attractiveness? And what about the luck, the social connections and the will of the individual?

Sorry for my bad English and thank you in advance.