Cain’s sixth chapter wandered a bit much for me. She first wrote of the complementary personalities of Eleanor and Franklin Roosevelt.
She wrote of Elaine Aron, who reframed high reactivity as sensitivity. Aron’s work finds sensitive people are more likely to be philosophical, or spiritual. They describe themselves as creative, or intuitive. They dislike small talk. They notice subtleties.
Cain writes of how highly reactive people may actually be thin skinned. They are more likely to blush. They have higher skin temperatures when exposed to new situations than low reactives.
Cain writes about how high reactive/passive animals and low reactive/aggressive animals might complement each other. They can maximize reproductive chances in different climates. Having watchful animals can help a herd survive. The reactivity seems to be inherited. Guppies that go from pike infested waters to pike free waters slowly become more outgoing. Guppies that enter pike infested waters become more cautious over just a couple generations.
There is even more in the chapter, for instance a few paragraphs about Al Gore and a few about Cain’s husband. At the end Cain makes the point that at a camp for introverts she misses extroversion. The anecdotes from the chapter were supposed to tell of how balance between introverts and extroverts brings strength to a group. I guess in hindsight I see this. I had trouble seeing the theme as the chapter developed, however.