What price perfection, and what size?

Had Melinda Messenger been born in the Middle Ages, she would never have become the national celebrity she is today. Rather, she would have crammed her breasts into a restricting corset in an attempt to reduce them to the then fashionable size of walnuts. A thousand years ago, large breasts were good only for wet-nursing. At a time when girls were considered marriageable at the age of 12, breasts the size of "virginal buds" were all the rage.

Over the intervening millennium the ideal size of the female chest has steadily grown, from medieval walnuts, to Renaissance "apples in the prime" and "little balls of ivory", when well endowed women would squeeze themselves into whalebone straitjackets, which often caused fractured ribs, bad breath and fainting fits, to the pneumatic grapefruits of the late-20th century. We are today in a state of near-hysteria about the female breast, according to an American academic, Dr Marilyn Yalom, when Page Three models become overnight celebrities and the new Wonderbra is delivered to American department stores in armoured cars.

In her new book, A History of the Breast, which traces its importance in society over the past 3,000 years, Dr Yalom argues that the farther breasts depart from their original nurturing function, the more men, and therefore society, become obsessed with the breast as erotic object. She points out that women in Africa and the Pacific walk about all day long with their breasts exposed, as they are needed for quick access by hungry children.

In these countries, other female parts, usually the buttocks, are the source of erotic potential. In the West, and especially the US, where fewer than a quarter of all mothers breast-feed their babies beyond the first few weeks of life, we have reached the stage when women will pay thousands of pounds, and risk their health, to increase their chest size to the supposedly ideal 38DD.

Conversely, when American plastic surgeons have been known to refuse women breast reduction operations until they get written consent from their husbands.

The author herself is a neat, petite, birdlike woman who on her own admission would have been prized in the Middle Ages for her tiny breasts. "When I go on lecture tours, I always catch members of the audience - men and women - trying to see what sort of breasts I have. People can't help it. The size of a woman's breasts has become one of the identifying markers of her entire persona." Is it pure chance that in her publicity photographs, and in the high-necked, dark, demure frock she is wearing today, it is impossible to see any flesh below the collarbone?

In her book she puts forward the argument that Western men, deprived of the maternal breast and never growing breasts themselves, suffer from "breast-envy". "In a way you have to feel sorry for men," she says. "They never grow out of this infantile obsession with the breast and spend their lives trying to return to a lost paradise. Even well educated male friends have admitted to me that often the first part of a woman's body they scrutinise is the chest, not the face. They say they can't help it. They are programmed that way."

Men, she says, are irresistibly drawn to the nurturing power of the female breast, and the bigger the better. Her own domestic situation, however, appears if not to contradict this argument, at least to give men a little more credit. Her husband Irvine, she says, "never was a leg man" and she often catches his eyes straying as a large-breasted woman walks past. Yet he has chosen to marry a woman who possesses no more than virginal bumps.

It is no accident that the author of this book is American. At least in this country and the rest of Europe, while no doubt a breast fetish exists, it is not illegal for women to take off their tops in public. Not only can women in the States be arrested for indecent exposure if they reveal their breasts "at or below the areola" but when Dr Yalom first started researching the book four years ago, women in most American states were still being arrested for breast-feeding in public. Not only that, but when a New York woman recently admitted to enjoying the physical sensation when her baby fed at her breast, she was charged with assault and had her baby taken into care. "I had just finished writing a book about women in the French revolution, when they were exhorted to breast-feed for the sake of democracy itself. Yet in my country you had naked breasts in magazines and at the cinema, but a nursing mother could be arrested for indecent exposure. That's weird."

That is weird, and goes a long way to explain some of the more extreme statements in the book, such as: "Women's breasts are for men's pleasure alone" and, "For most of Western history women's breasts have been controlled by men." Although Dr Yalom does acknowledge the "delicious pleasure" a woman's breasts can give her, she devotes an entire chapter to the "erotic breast" with just one single reference to a female perspective. In her defence, she says that she scoured several centuries of literature on the breast, desperate to find "anything, anything at all, a poem, a fragment from a novel" where a woman expressed pleasure in her own breasts. The only female-authored reference she can find is in fact written by a lesbian nun, describing how she remembers her lover caressing her "little breasts." The Sun would have had a field day.

Of male-authored references to the joys of the female breast, we have in abundance, particularly memorable are the poems of the 16th-century French writer Clement Marot, whose descriptions of the female breast have little bearing on reality:

A little ball of ivory

In the middle of which sits

A strawberry or cherry.

Here are a few others, all of which, rather than making you bristle with indignation, are so far from the real world as to be laughable: "round as orient pearls, as soft as down"; "alabaster orbs"; "fair apples in the prime"; "lawns of milk"; and - my favourite - "cherrylets".

It is only in the last 30 years, says Dr Yalom, that we find women describing the erotic potential of their own breasts, and even then, female writers are aware of the dual purpose of the breast:

All the years of girlhood we wait for them, /Impatient to catch up, to have power /Inside our sweaters, to replace our mothers... /When the lovers lick them /And bring us there, there, in the fragrant wet, /When the babies nuzzle like bees.

That poem, by Alicia Ostriker, refers to something that Dr Yalom only glosses over - that because men love women's breasts, then possessing breasts does give us a certain power. And, hell, it's fun to don a Wonderbra from time to time and watch male colleagues desperately trying to prevent their eyes from being drawn to our chests.

Although the prevailing modern fashion for breasts is large and gravity- defying, from her research Dr Yalom has discovered that the fad for smaller breasts comes around about once every 60 to 80 years, and we are due for another bout of boyish chests in about 2020.

She also believes, however, that after centuries of the erotic focus, the image of the breast will gradually mutate into something more sinister as the incidence of breast cancer rises, and women - and their partners - will live in fear of what their breasts may have in store for them. She even argues that today's obsession with large breasts is partly owed to society trying to laugh off the fatal potential of the breast.

"Today," concludes Dr Yalom, and not a little sententiously, "The breast reflects a medical and global crisis. We are anxious about our breasts just as we are anxious about the future of our world."

Try telling the man ogling Page Three that in reality his interest in the female form reflects a deep-seated fear about the potentially fatal nature of the female breast and, by extension, the future of the world itself.

`A History of the Breast' by Marilyn Yalom is published by Pandora, price pounds 12.95. Breast Cancer Awareness month begins this week