Theodor Geisel (otherwise known as Dr. Seuss) spent his workdays ensconced in his private studio, the walls lined with sketches and drawings, in a bell-tower outside his La Jolla, California, house. Geisel was a much more quiet man than his jocular rhymes suggest. He rarely ventured out in public to meet his young readership, fretting that kids would expect a merry, outspoken, Cat in the Hat–like figure, and would be disappointed with his reserved personality. “In mass, [children] terrify me,” he admitted.

Schwartz's research suggests something important: we can stretch our personalities, but only up to a point. Our inborn temperaments influence us, regardless of the lives we lead. A sizeable part of who we are is ordained by our genes, by our brains, by our nervous systems. And yet the elasticity that Schwartz found in some of the high-reactive teens also suggests the converse: we have free will and can use it to shape our personalities.

Scores of studies have shown that venting doesn't soothe anger; it fuels it.

The bias against introversion leads to a colossal waste of talent, energy, and happiness.

Another study, of 38,000 knowledge workers across different sectors, found that the simple act of being interrupted is one of the biggest barriers to productivity. Even multitasking, that prized feat of modern-day office warriors, turns out to be a myth.

In our society, the ideal self is bold, gregarious, and comfortable in the spotlight. We like to think that we value individuality, but mostly we admire the type of individual who’s comfortable "putting himself out there."

I've never given a speech without being terrified first.