On a trip to Italy a few years ago, my partner and I peered into the faraway distance at that famously angled phallus that is the Leaning Tower of Pisa, when suddenly we became aware of a small scene unfolding before us. A young woman’s stiletto heel had become lodged in the cobblestones. Oh my. With an enormous, flashy handbag dangling in the crook of her arm, there she was, giggling in situ, gesticulating wildly to her older male companion, who was endeavoring to extract the damsel’s foot as if it were made of glass. Not all women are so insufferably vain, of course, nor all men so chivalrous, but our love affair with high heels… now there’s a near universal.

But… why? Until that summer day in Pisa when this very special individual got her foot stuck in a medieval thoroughfare, it hadn’t even occurred to me to ask why high heels and femininity should go together. It was just obvious that they did. The standard feminist conjecture has actually been around for some time. High heels, we’re told, are a symptom of an oppressive male society that seeks to literally hobble women, not so unlike the barbarian practice of Chinese “foot-binding” in which little girls’ feet are bound so tightly that, rather than grow naturally, their appendages wither into tiny, deformed, often useless stumps. Atrocious. It turns out this classic view may not be entirely right about high heels, though. Take the point about men wanting women to be unstable on their feet in order to control them. True, it’s probably best to kick off one’s high heels when being pursued by an axe murderer, but high heels aren’t exactly forged upon a woman’s soles, nor do most have to be held down by misogynist pigs to have their feet inserted into a Christian Louboutin or a Manolo Blahnik. What’s more, the male preference for women with small feet, long considered to be a universal bias in mate selection, has recently been called into question. As UCLA anthropologist Daniel Fessler has pointed out, from an adaptive perspective, it would actually make more sense for men to have evolved a preference for women with large feet, given that these surefooted females are less prone to falling during pregnancy and thus putting their own genetic future at risk. Indeed, contrary to what feminist critiques might predict, some male-dominated societies that have had little exposure to Western media favor women with large feet. (By contrast, men who brandish average-sized feet are seen as most attractive the world over, a finding that appears to contradict one very big rumor. I’ll save that for another day.)

Since high heels are known to decrease perceived foot size, and since men even in some extremely sexist cultures find women with small—more unstable—feet unattractive, our answer to the why question of high heels can’t simply boil down to the crafty hobbling strategies of women-hating bastards. So what is it, then, that makes ladies so eager to stuff their tender feet into these contraptions that pose real and significant health risks? With too-frequent use, these stylish yet merciless objects have been known to convert the perfect female foot into a hammer-toed, callused hoof replete with bunions and corns; they’ve led to shattered ankle bones, caused chronic lower back pain, and even bred osteoarthritis of the knees in some women. Aside from these and other anatomical horrors, high heels are just weird when you stop to think about it. Imagine being an onlooker at one end of a large hallway teeming with beautiful women who are pleasantly perambulating your way. They’re dressed to the nines except for the curious omission of their shoes. Not only are they in their bare feet, but there’s also something off about the way that they’re walking. It’s… unnatural. Their soles are rigidly arched such that their heels are airborne and their weight is balanced precariously on the metatarsal region just behind their toes. Strange, yes. But if you could see through the train of Stuart Weitzmans and Jimmy Choos worn by the next gathering of oblivious starlets who happen to traipse down the red carpet, this surreal podophilic vision is precisely what you’d glimpse.

Perhaps the best question, then, is this: What are the benefits for women in wearing high heels? A 2013 study in Evolution and Human Behavior by the psychologist Paul Morris and his colleagues put a spur in the side of this, ahem, important issue. There must be some adaptive payoff for women, reasoned these authors, that effectively trumps the health risks that come with wearing high heels and that can also explain the sheer perseverance of this female shoe style through the centuries and across so many different cultures. Although fashion trends come and go—and I suspect you’ll soon be able to count the new look of straight men in high heels among the more ephemeral ones—those that endure over time, Morris and his colleagues surmise, possess attributes that are in basic harmony with human mate selection. There’s a reason (wise) women no longer wear shoulder pads: this fashion style went against the basic evolutionary grain, one that, over millennia, programmed human minds to innately view big-shouldered women as, well, manly. And that isn’t a turn-on for the average heterosexual male. In other words—and I say this as someone who once wore candy-apple red parachute pants in public… and proudly so at that—although the cultural transmission of a given fashion trend can in some cases lead to massive, even worldwide, replication, for a style to have any real staying power it must also be consonant with the fundamental ways in which our brains evolved to work.

To get at the primeval logic driving the timeless appeal of high-heeled women, then, Morris and his team came up with what’s called a “point-light display” study design. This involves a person being marked at strategic points of their anatomy with what is essentially a set of glow-in-the-dark dots. The researchers had twelve different women of different ages and sizes serve as point-light models, placing the dots at specific body parts that are relevant to our species’ distinctive locomotive pattern. (These included “the lateral malleolus of the ankle”; “the greater trochanter”; “the anterior superior iliac spin;” and so on). All of these women—experienced high-heelers, by the way—were filmed alone in darkness as they walked at a normal pace on a treadmill, so that only their artificial point lights were visible. And each did so twice: once while wearing a pair of flat shoes and once in a set of 6-cm high heels. These point-light video clips were then shown, in a completely random order, to a group of naïve twenty-something observers (15 men and 15 women). The angle they viewed was of the female model walking towards them, and the participants were asked to judge, basically, how hot was each woman’s trot in the clip being shown.

On analyzing these ratings, Morris and his colleagues found that the video clips of the walks in high heels were judged to be significantly more attractive than those in flats. That may sound like a no-brainer, but it’s important to remember that the observers had no idea what they were actually watching. Some may have secretly pieced together that “this is the gait of a woman wearing high heels, therefore she must be sexy” but it was never explicitly stated. Instead, the observers were told just the basic facts: something on the order of, “using only point-light displays to inform your subjective decisions, you’re about to judge the attractiveness of women’s walks.” The participants also had no idea that the women were doubled-up in the two key conditions (high heels vs. flats), believing instead that they were viewing 24 different female models. Nonetheless, every model was judged to have a more attractive walk in high heels compared to their own walk in flats. In fact, this high-heel hottie effect panned out even after controlling for other physical traits that might interfere with the attractiveness ratings. For example, although the walks of women with higher BMIs (“Body Mass Index,” basically, degree of relative fatness) were judged to be less attractive overall than those with lower BMIs, even the high-heeled strides of the heavyset women were seen as more attractive than their own flat-footed gaits.

Those findings still don’t really address our original question, however. We now know that the sex appeal of a woman in high heels has something to do with the way that this distinctive shoe fashion makes a woman walk. But what is it about the high-heeled gait that makes it so singularly seductive? To Morris and his co-authors, it all has to do with sex. These are evolutionary theorists, so, yes, of course it does. Still, it doesn’t take a Darwinian scholar to see the clear link between sex and stilettos. Consider a study done back in the early 1980s, for example, in which researchers studying how women were depicted in porno mags were surprised to discover that over half of the randy rags then on the market featured cover models wearing high heels… and not much else. Less raunchily, the connection between female sexuality and high heels is all around us, and like many unnoticed aspects of our social behaviors, such “hidden obviousness” can be an embarrassment of riches. In many parts of the world, high heels are the bread and butter of a woman’s dressy wardrobe. And one doesn’t usually dress up with the aim of looking sexually unattractive. Likewise, the fact that many parents won’t allow their daughters to wear high heels until they’re mature enough to do so—and it’s rather cringe-inducing for most of us to see a preteen girl in high heels—betrays that same implicit tie-in with sex. None of this is conscious, mind you. Nature doesn’t care if you know the secret algorithms underlying your mating decisions; you’re just fodder in the great machine.

So according to Morris, women in high heels have a sexier walk than those in flats. That’s what the construct of “attractiveness” means at its core, right? Digging their heels into the matter even further (that’s awful, my apologies), the researchers began to look more closely at what drove the high-heeled hottie effect from their first study. This time, they randomly assigned a new batch of 120 men and women to a condition in which they saw a single video clip, footage again showing glow-in-the-dark treadmill walkers. Each observer was asked one simple question: Is the walker you see on the screen a man or a woman? Unbeknownst to them, however, all of the figures in the videos were in fact female. It was the same stimulus set of the 12 women walkers from before, each in a separate clip shown in high heels or flats (so there were again a total of 24 video clips, but each observer saw only one of these).

It was a simple but clever hypothesis. The authors predicted that the observers would be more likely to misidentify the flat-footed female walkers as men than they would the high-heeled walkers. And that’s what they found. “When wearing high heels compared to flats,” write the authors, “women take smaller and more frequent steps, they bend their knees and hips less, and more rotation and tilt occur at the hips.” Translation: women in high heels walk really girly. But that’s more meaningful than it sounds. By exaggerating the normal female gait, high heels serve to falsely enhance our perception of the wearer’s femininity. And like other overt signs of femininity, such as those big fake mammary glands some of you people are so fond of, donning high heels can add points, albeit deceptively, to a woman’s reproductive value.

Oh the humanity. It’s even more of an animal than we thought.