People are not always self-interested, but still have certain altruistic favor, which has certain gender difference. The everyday experience "men are rational animals, while women are sentimental animals" is proved to some extent in the experiments, while the difference is not quite significant in statistics. It shows that girls are more slightly self-interested than boys, while boys are more completely self-interested than girls if they are self-interested at all. The longer one works in the team, the stronger his altruistic favor is. Managers should improve the team work by full use of people's altruistic favor, which can improve the management performance.