The drive to excel is rooted in numerous evolutionary and psychological factors. These factors include: a desire for social dominance, the drive to mate and produce offspring, and a need for security.
Evolutionary biologist E.O. Wilson theorises that humans' desire to excel is related to social hierarchy. Those who excel occupy a higher position in the community than those who do not. A higher position in the community means greater access to resources such as money, social influence, and power. Wilson notes that the drive to excel is one that humans share with other social primates. In the case of other primates, those who occupy a higher position in the hierarchy have greater access to food and shelter, as well as a wider choice of mating partners.
Not psychological, but biological. The need to excel is genetic competition at it's best.