It's one of the worst-kept secrets of family life that all parents have a preferred son or daughter, and the rules for acknowledging it are the same everywhere: The favored kids recognize their status and keep quiet about it - the better to preserve the good thing they've got going and to keep their siblings off their back.

As the National Football League and other pro sports increasingly reckon with the early dementia, mental health issues, suicides and even criminal behavior of former players, the risk of what's known as chronic traumatic encephalopathy (CTE), is becoming clear.

Kids are anarchy writ large.

I was born in the U.S., my wife was born in Mexico and emigrated here when she was in college, and my daughters were born in New York City. That makes them passport-carrying, natural-born, eligible-to-run-for-president Americans. But they're also Mexicans and they like that just fine.

Introverts listen better, they assess risks more carefully, they can be wiser managers. It's not for nothing that the Silicon Valley billionaires are so often the retiring types.

Spare a thought for the poor introverts among us. In a world of party animals and glad-handers, they're the ones who stand by the punch bowl. In a world of mixers and pub crawls, they prefer to stay home with a book. Everywhere around them, cell phones ring and e-mails chime and they just want a little quiet.

When we're awake, cortisol can fragment memories - one reason eyewitness crime scene accounts are so unreliable. But at night that very fragmentation allows creative recombinations of ideas.