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.

Every batch of sperm represents an opportunity for genetic typos - called de novo mutations - to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65 - and it keeps climbing from there.

There are a lot of ways to make people not like you, but one of the most powerful - if least fair - is to be really, really successful. Nobody resents the guy who just lost his job. But the guy whose Internet start-up made him a billionaire at 25? That's a whole different kettle of envy.

Kids whose puberty begins too soon face not just psychological risks, but physical ones too, with an increased likelihood of cancer, as well as skeletal changes that could prevent them from attaining their full adult height.

Part-black generally means all-black in Americans' minds. Just as part-Asian or part-Hispanic or part-anything-else usually puts individuals in those minority-groups' camps.

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.

There may be no more-radioactive term in the English language than what we now almost always refer to as the 'n-word' - itself a coy means of linguistic sidestepping that is a sign of how perilous it is to utter the thing in full, even in conversations about language.