This is so obvious it should go without saying. But in the world of behavioral science nothing goes without saying, so there have been hundreds of studies devoted to proving precisely this point. The bibliography of the definitive work on the subject runs to 55 pages, almost exactly matching the number of citations in “The Bell Curve.” In virtually any conceivable set of circumstances, research shows that you’re better off being good-looking. Convicted of a crime? When male college students were asked to decide on a sentence for women supposedly convicted of identical crimes, they gave the homely ones 50 percent more jail time than the pretty ones. Bitten by an animal? Men, approached by a female researcher. dripping blood after a supposed attack by a laboratory rat. were more likely to offer help if the woman was beautiful. Looking for work? Good-looking men and women generally earn more than homely ones: tall men are better paid than short ones. Teachers who were asked to evaluate hypothetical children with identical academic records but different pictures consistently rated the better-looking child as more intelligent.

Of course, this research merely ratifies what scientists already know from watching “Entertainment Tonight.” There are many more obscure, miserable and impoverished geniuses in the world than underappreciated beauties. Intelligence, for all its power, manifests itself only through the transforming medium of work. Getting into Harvard Law School is only a step toward baring it made: you still have to get through the next three years and then embark on a series of 80-hour weeks at Sullivan & Cromwell. True, a similar claim is sometimes made for beauty. One woman whose married name you would recognize from the business pages complained to a writer once about the suggestion that her biggest achievement in life was meeting her future husband. “That makes it sound like it was easy,” she said.

But that’s not exactly the same thing as writing “Crime and Punishment.” Dostoevsky labored for decades, in and out of debt and prison, before people woke up to the fact that he was the greatest writer in the world. While still in high school, Claudia Schiffer stepped onto the dance floor of a Dusseldorf nightclub, where she was spotted by a modeling agent, and within two years had become one of the most admired and famous women in the world. Obviously Schiffer’s career path-she recently announced her intention to sell her autobiography-beats Emily Diekinson’s strategy of remaining virtually unknown until after her death. But not so obviously, Schiffer makes even someone like Goldie Hawn look like Madame Curie. For all I know, Schiffer may have an IQ of 250. But why would she, or anyone, go to the trouble of acting when there’s just as much money and fame to be made slouching against a tree in a pair of blue jeans?

Needless to say, a society ranked by looks is even less democratic than one organized by IQ. Intelligence is distributed in a bell-shaped curve, but beauty is bestowed discontinuously, on the star system. Peter Jennings is very good at what he does, but there are probably other people who could do it almost as well. In looks, though, either you’re Peter Jennings or you’re not. Those who are not console themselves with the thought that beauty is an entirely subjective and culturebound quality. Unfortunately, research actually suggests the opposite. David Marks, an economist who has studied the question extensively, concludes that within cultures, and even to some degree between them, there is pretty good agreement on who is and isn’t beautiful. . . which, he adds, “is good news for those who are.”

It’s good news because beauty, along with size, is the one human quality immediately apparent on first encounter. Only an IQ test can tell if you belong in Murray and Hermstein’s “cognitive elite,” but if you’re beautiful, a mirror tells you all you need to know about your chances in life. And you don’t even need a mirror; you can see it in the eyes of the people you meet. If Murray doubts this, let him show up at a trendy restaurant like Indochine at 9:30 on a Friday night and try to get a table on the strength of his IQ. People who aren’t beautiful can have perfectly useful careers in dull but worthy professions, such as academia or journalism. They can have friends, lovers and satisfying family lives. And if they’re also smart, lucky and hardworking, someday the velvet rope may part and admit them to life’s inner circle. And what will they find there? A bunch of 23-year-olds in black sweaters who were waved in by the doorman.

Murray and Hermstein were right about one thing: it pays to choose your parents carefully.