It's a deep and all but certain truth about narcissistic personalities that to meet them is to love them, but to know them well is to find them unbearable. Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.

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.

My family went through divorces and remarriages and the later, blended home - and then watched that home explode, too.

The golden child may be the oldest one, unless it's the youngest. It may be the toughest one, unless it's the most sensitive. It's not even necessary that Mom and Dad have the same favorite - and typically they don't.

Since narcissism is fueled by a greater need to be admired than to be liked, psychologists might use that fact as a therapeutic lever - stressing to patients that being known as a narcissist will actually cause them to lose the respect and social status they crave.

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

We are all born with an innate understanding of interpersonal equity - the idea that if you lend me your rake today, I'll respond in kind when you come to borrow my shovel tomorrow. Or nearly all of us are born with that. Psychopaths aren't.