chicken-and-egg question不是“鸡和蛋的问题”，指的是“先有鸡还是先有蛋的问题；因果难定的问题”。这一表达源于一个深奥的问题，“Which came first—the chicken or the egg?”

【例句】
Does she eat too much because she's unhappy, or is she unhappy because she eats too much? I suppose it's a chicken-and-egg question.
她是因为不开心才吃很多东西，还是因为吃很多东西而不开心？我看这个因果关系很难界定。

This raises an obvious chicken-and-egg question, but the smart money is on culture shaping the brain, not vice versa.
这就引发了一个明显的‘先有鸡或先有蛋’谜题，而实情是文化塑造大脑，而非相反。