And that’s why yet another theorist, German-born psychologist Erik Erikson, came up with his own eight-stage theory of development, that goes all the way from infancy to old age.

这就是为什么另一位理论家，德国出生的心理学家埃里克埃里克森提出了他自己的八阶段发展理论，从婴儿期到老年期。