translation.en: But you have to think evolutionarily, you have to think, what hard job that has to be done -- it’s dirty work, somebody’s got to do it -- is so important to give us such a powerful, inbuilt reward for it when we succeed.
translation.zh: 你必须从进化的角度来想，你得想，什么困难的活必须被完成—— 这是一个脏活，而且必须有人来完成它—— 以至于当我们完成的时候，给我们一个强烈的内在奖励那么重要。