Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started.

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.

Credit or debit cards, for starters, are nothing short of shoppers' Novocain. Even in the age of digital purchases and virtual money, we still attach a special value to dirty paper with pictures of presidents on it. Handing some of that to a cashier simply hurts more than handing over a little sliver of plastic.

Athletes often start life at the opposite end of the wealth and prestige spectrum, but as soon as they exhibit an unusual talent for swinging a bat or sinking a free-throw they may find that the rules have been suspended for them. They are waved through school and into the pros, and incidents of bad behavior are overlooked or covered up.

In both children and adults, there can be a hard-to-deny link between a robust sense of hope and either work productivity or academic achievement.

Vaccines save lives; fear endangers them. It's a simple message parents need to keep hearing.

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.