No one wakes up in the morning and decides, “Today I’ll put the needs of the whole world foremost, disregarding my own,” or “I can’t wait to stuff down my anger and frustration and put on a happy face instead.” Nor is anyone born with such traits: if you’ve ever met a newborn infant, you know they have zero compunction about expressing their feelings, nor do they think twice before crying lest they inconvenience someone else. The reasons these habits of personality, as we might call them, develop and grow to prominence in some people are both fascinating and sobering.
