I’m simply going to quote the section on creating the “ideal woman” from the Screwtape Letters. You can purchase the book in multiple formats here.
In a rough and ready way, of course, this question is decided for us by spirits far deeper down in the Lowerarchy than you and I. It is the business of these great masters to produce in every age a general misdirection of what may be called sexual “taste”. This they do by working through the small circle of popular artists, dressmakers, actresses and advertisers who determine the fashionable type. The aim is to guide each sex away from those members of the other with whom spiritually helpful, happy, and fertile marriages are most likely.
Thus we have now for many centuries triumphed over nature to the extent of making certain secondary characteristics of the male (such as the beard) disagreeable to nearly all the females—and there is more in that than you might suppose. As regards the male taste we have varied a good deal. At one time we have directed it to the statuesque and aristocratic type of beauty, mixing men’s vanity with their desires and encouraging the race to breed chiefly from the most arrogant and prodigal women. At another, we have selected an exaggeratedly feminine type, faint and languishing, so that folly and cowardice, and all the general falseness and littleness of mind which go with them, shall be at a premium.
At present we are on the opposite tack. The age of jazz has succeeded the age of the waltz, and we now teach men to like women whose bodies are scarcely distinguishable from those of boys. Since this is a kind of beauty even more transitory than most, we thus aggravate the female’s chronic horror of growing old (with many excellent results) and render her less willing and less able to bear children. And that is not all.
We have engineered a great increase in the licence which society allows to the representation of the apparent nude (not the real nude) in art, and its exhibition on the stage or the bathing beach. It is all a fake, of course; the figures in the popular art are falsely drawn; the real women in bathing suits or tights are actually pinched in and propped up to make them appear firmer and more slender and more boyish than nature allows a full-grown woman to be.
Yet at the same time, the modern world is taught to believe that it is being “frank” and “healthy” and getting back to nature. As a result we are more and more directing the desires of men to something which does not exist—making the rôle of the eye in sexuality more and more important and at the same time making its demands more and more impossible. What follows you can easily forecast!