Is she really going out with him?

There has long been the social expectation that couples should match each other in terms of brains and beauty. But there have always been exceptions, and now the Americans have a word for it: "down-dating" means going out with someone who is below your physical or intellectual standards, theoretically to boost your own ego.

Blond icon Marilyn Monroe did it in the 1950s when she married the awkward, bespectacled playwright Arthur Miller, while in the 1990s there have been a host of celebrity down-daters. Julia Roberts flouted convention when she married the offbeat, hatchet-faced musician Lyle Lovett, while supermodel Claudia Schiffer opted for David Copperfield, a man with a big nose and a host of party tricks. Uptown girl Christie Brinkley married an unprepossessing Billy Joel, and stunning Eva Herzivoga has been stepping out with craggy Bon Jovi drummer, Tico Torres. But is this really just a case of women emphasising their beauty by dating unattractive men?

"It's what I call the Mickey Rooney syndrome. He was a short, ugly guy who dated all the beautiful women in Hollywood and married Rita Hayworth. Ugly men learn how to treat a woman well in a way she likes and make her feel attractive," says Wendy Fonarow, a teaching fellow in cultural anthropology at UCLA in Los Angeles. "Julia Roberts met tons of pigs, then she meets a guy who treats her like a lady. No wonder she married him in three months."

With seemingly unequal relationships there is always a pay-off. A less attractive man can match a beautiful woman in terms of wealth and status - witness MPs and businessmen pairing off with models. Until Madonna celebrated the toy boy in the 1980s, it was much less common the other way round, but now with increased earning power and economic status, women too are taking pretty boys for good sex and social decoration.

What is less quantifiable and more tricky is the question of intelligence. "In a society that posits that men are supposed to be more intelligent, it takes a very secure man to go out with a woman who outshines him intellectually. If you pick someone less smart you can have a sense of mastery or dominance, hence older men with younger girls," says Fonarow. Many professional men who claim to want their intellectual equal end up marrying someone less bright or ambitious than themselves.

"Men don't necessarily need a woman to be intellectually stimulating," says Professor Windy Dryden, psychotherapist and author of How To Untangle Your Emotional Knots (Sheldon Press). "An academic might get stimulation elsewhere, but needs a mate to be a good mother and housekeeper. Those kind of traditional roles will work out if the wife has similar expectations." Woe betide the wife if she does a college degree, or like Melanie Griffith in Born Yesterday, she wises up. "Then the couple's unspoken equilibrium is jeopardised," says Dryden. It is much rarer for an intelligent woman to be satisfied with a less stimulating man. While men have been trained to rate looks at a premium, women are more likely to value personality. "There's more social stigma attached to a woman dating a dumb guy or a man with no means," says Fonarow. If a woman does "down-date" it is as a recourse, when her male peers are "taken". According to Robin Russell, lecturer in psychology at Goldsmiths' college, down-dating is a minority phenomenon. "We did a survey of 1,300 British married couples and found that the attractive marry the attractive, the rich marry the rich, and most are in the same age range. Similarity is the general rule. How many young women really have sugar daddies? The average 18-year-old woman wants a 20-year-old, not a 50-year- old-man with a Ferrari."

Down-dating, it seems, is a short-term answer to particular needs. Monroe divorced Miller after four years; Roberts and Lovett lasted less than two years; Christie Brinkley ditched Billy Joel for the distinctly more uptown Rick Taubman; Schiffer and Copperfield are no more. Meanwhile, Eva Herzigova and Tico Torres are poised to tie the knot. With the best will in the world, let's hope their pre-nuptial agreements are all in order.

'She has more book-learning than I do, but I'm well-educated in a backwoods way'

Sindi, 35 (right with Rex), a production editor of a newspaper, earns approximately pounds 40,000 a year. Rex, 49, a cowboy on a ranch near Tuscon, Arizona, earns about $8,000 (pounds 5,400) a year. They have been together for six months and Sindi plans to join him in the US early next year.

SINDI: I met Rex when I was on holiday at the ranch. I'd only been there half an hour when he walked round the corner and my heart missed a beat. He was very tall, had a great big white Stetson on, spurs, and a loud blue stripey shirt. I heard his spurs jingling and that was it, basically. We spent the next two weeks together, and he came to London a couple of months later. I wanted to get him over here to see if it was him I was in love with, or just the image of the rough and tough cowboy. But when he came over we had a fantastic time and and he fitted in well. There are huge differences in the way we've been brought up, how we've been educated and the money we earn. All he owns is a truck and a saddle, whereas I have a high-powered job in London. It's all relative, though. I respect Rex's attitudes and values. He lives each day as it comes, doesn't worry about where the next dollar is coming from, whereas so much of my life has revolved around money. I want to get out of the rat race and have a simpler lifestyle.

I might know authors and film directors, but he knows about the country and the wildlife. With Rex, he's so honest, what you see is what you get. He's bright, but he doesn't pretend to be well-read or extremely clever. In the past I've gone out with people and tried to be something I'm not. I would match them on certain levels, but there was always something lacking. With Rex I feel comfortable, I can be myself totally.

REX: When I first met Sindi I was very taken with her. I thought, wow, nice-looking lady! I'd never been around someone so vivacious and full of energy. We met, rode horses, I took her dancing. By the end of the first evening I knew there were a lot of differences between us, but that didn't bother me. She's high up in what she does, but I feel comfortable in my work, as she is in hers.

She has more book-learning than I do, but I'm well educated in a backwoods way. I know a lot about veterinary work, how to doctor horses, different ways of surviving in the cold and heat. I've been cowboy-ing since I was 13. I've spent a lot of time or my own, I'd maybe spend two months not seeing another human, living in the deserts and mountains looking after cattle. I've had my fill with chasin' and doin', hell I've been all over the West, now I'm ready to settle down. I think Sindi will fit in well, all of my friends love her. We'd probably live in Tucson, or work on a guest ranch. I can teach her to ride, to hunt and fish, but she can bring so much into my life, too.