Katy Kay

Claire figured she is high in oxytocin, and Katty agreed with that self-assessment. “I crave affection, contact, and intimacy, and tend, to a fault, to view the world around me with the rosiest of lenses. It can cloud my judgment sometimes,” Claire admitted. “But I’m guessing I’m low in serotonin, because I can be quite anxious. I’ve struggled with it over the years, and my parents both suffered from depression. I think my overall makeup would not add up to a highly confident genetic profile. I’ve probably created whatever confidence I have.”

We were both certain that Katty is a warrior. From Claire’s point of view especially, Katty thrives on risk and challenge. “I figure I’m also pretty high in serotonin—I’m not overly anxious,” says Katty, “but I don’t think I have the warm and fuzzy oxytocin gene. I’m fairly matter-of-fact.”

The most astonishing science, with profound promise for cracking the confidence code, proves that all of us can rewire our brains, even as adults. Orchid or dandelion, good mother or bad—when we change our thinking and develop new mental habits, that effort creates physical changes in our brains.