Science has yet to isolate the Godiva Chocolate or Prada gene, but that doesn't mean your weakness for pricey swag isn't woven into your DNA. According to a new study of identical twins, it's less TV ads or Labor Day sales that make you buy the things you do than the tastes and temperaments that are already part of you at birth.

Some of the most rewarding times my brothers and I have are when all of us get together, and we can see what we've been building genetically and culturally.

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.

We're learning how important it is both to preserve sibling relationships if they work and repair them if they're broken. We're also learning a lot about nonliteral siblings - stepsiblings, half-siblings - and the surprising power they can have.

Narcissistic personalities usually do do better than you and me and the average person. We've always seen it in the office. The person who speaks up more in meetings, the person who's charismatic, who can sell an idea with more excitement and energy.

Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.

Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used.