Marriage is a lot of things - a source of love, security, the joy of children, but it's also an interpersonal battlefield, and it's not hard to see why: Take two disparate people, toss them together in often-confined quarters, add the stresses of money and kids - now lather, rinse, repeat for the rest of your natural life. What could go wrong?

Marriage is a lot of things - a source of love, security, the joy of children, but it's also an interpersonal battlefield, and it's not hard to see why: Take two disparate people, toss them together in often-confined quarters, add the stresses of money and kids - now lather, rinse, repeat for the rest of your natural life. What could go wrong?

Jellyfish serve as a model for bioengineers for the same reason yeast were once so valuable to geneticists: they're simple to deconstruct.

Narcissism falls along the axis of what psychologists call personality disorders, one of a group that includes antisocial, dependent, histrionic, avoidant and borderline personalities. But by most measures, narcissism is one of the worst, if only because the narcissists themselves are so clueless.

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.

Certainly, people can get along without siblings. Single children do, and there are people who have irreparably estranged relationships with their siblings who live full and satisfying lives, but to have siblings and not make the most of that resource is squandering one of the greatest interpersonal resources you'll ever have.

Paul McCartney had a baby when he was 61; Rod Stewart was 66; Rupert Murdoch was a stunning 72. Not only does that mean they'll have less stamina than the average dad, that means they'll, well, check out a lot sooner too.