Personality is to large extent inherent — A-type-parents usually bring about A type offspring. But the environment must also have a profound effect, since if competition is important to the parents, it is likely to become a major factor in the lives of their children.
One place where children soak up A-characteristics is school, which is, by its very nature, a highly competitive institution. Too many schools adopt the 'win at all costs' moral standard and measure their success by sporting achievements. The current passion for making children compete against their classmates or against the clock produces a two-layer system, in which competitive A-types seem in some way better than their B type fellows. Being too keen to win can have dangerous consequences: remember that Pheidippides, the first marathon runner, dropped dead seconds after saying: "Rejoice, we conquer!"