A hero, an antihero, and a psychopath walk into a bar. Which one orders milk?

Your answer depends on how you like your tough guys. But if the question alone sends a tingle down your spine, it could be because you’ve seen one of the many violent movies where milk—an ostensibly wholesome drink—becomes an unlikely accessory to bloodshed. As Now You See It noted in a widely circulated video essay earlier this year, the nourishing stuff we pour on breakfast cereal has, in Hollywood shorthand, become the drink of both youthful innocence and—somehow—those who vanquish it.

When we talk about “characters” drinking milk in movies, though, it’s important to note that we mean “men;” women can, for the most part drink it or not, and no one notices or cares. But maybe because it’s what babies drink, or maybe because of its feminine source, milk seems to be a liability for guys looking to prove their masculinity or bond with other men. Drink it and you’re a wimp or a pervert—unless, of course, you’re so manifestly badass that you don’t need your drink choice to do your work for you.

These is-he-or-isn’t-he dynamics are at work in the 1939 Western Destry Rides Again, to cite one classic example. Jimmy Stewart plays Tom Destry, Jr., a mysterious outsider that the sheriff, who also happens to be the town drunk, has called in to rid the town of its criminal elements. But the apparently mild-mannered deputy, who arrived by stagecoach brandishing a parasol, doesn’t even carry a gun, and the townspeople are, needless to say, skeptical. When the bartender taunts, “What’ll you have—milk?” Destry doesn’t flinch, replying with a steely, “Yes, I think I will.”

The bar erupts in laughter, and Destry is handed a bucket and a mop, the suggestion being that that’s the only sort of “cleaning up” that a pansy like him will be doing in these parts. But, inevitably, there’s more to our hero than meets the eye: The son of another legendary lawman, Destry soon reveals himself to be a crack shot and ultimately abandons his pacifism to avenge the murder of the hapless sheriff and oust the local strongman. See, he was a tough guy after all!

In a moral universe organized around paired opposites (lawmen and outlaws, valor and cowardice), milk serves as an obvious foil for booze, the other thing we might expect rugged gunslingers to be knocking back. But it turns out that movie heroes haven’t always been drinkers. Some of the earliest Westerns were pretty strongly anti-vice, and during the brief vogue for the “singing cowboy” pictures of the 1930s and ’40s, the “cowboy code” marketed by Gene Autry’s publicity team to young fans stipulated that a cowboy “must keep himself clean in thought, speech, action, and personal habits.” On screen, the character Hopalong Cassidy ordered milk or sarsaparilla, and in real life the actor who played him even became a spokesman for a dairy company.

A crooner with a milk mustache isn’t exactly what comes to mind when you picture a cowboy in a shootout, because another vision—of the guy who coolly takes someone out without ever putting down his whiskey (like Gregory Peck’s Jimmy Ringo in The Gunfighter)—is the one that ultimately captured audiences’ imagination. But if you don’t believe me, take it from Roland Barthes, who in his 1972 essay “Wine and Milk” acknowledges the role of manly movie violence in making milk into a symbol of power. “Some American films, in which the hero, strong and uncompromising, did not shrink from having a glass of milk before drawing his avenging Colt, have paved the way for this new Parsifalian myth,” he writes.

In The American Western, Stephen McVeigh argues that, ironically, it was Prohibition that first turned moviegoers off of morally true milk drinkers and on to alcoholic bad boys. Upstanding citizens who disagreed with this particular law found themselves identifying with criminals for the first time, and the gangster movie was born, followed by film noir. With the new vogue for darker, more psychologically complex characters, protagonists in Westerns came to more closely resemble gangster antiheroes—dangerous, lonesome types who weren’t above benders or a little light torture of deserving enemies.

Zillions of ethically imperfect, hard-boiled male protagonists later, bar-order-as-character-development became its own kind of cliché. (The 1985 Western spoof Rustlers’ Rhapsody pokes fun at the well-worn trope with a saloon scene in which the cowboy protagonist cheerfully switches from milk to “a tall glass of warm gin with a human hair in it” once he realizes he’s in one of those “really tough guy bars.”)

Over time, then, filmmakers who really wanted to surprise us with What the Hero Drinks had to work harder for it. Probably the most famous example of milk used for shock value in this way is the opening scene of A Clockwork Orange, where we meet Alex and his merry band of teenage delinquents in a bar that serves drug-laced milk dispensed from statues of naked women. Alex’s look—the fixed smirk, those long lashes on just one eye—is immediately unnerving, but it’s a twist on the classic milk-liquor juxtaposition that confirms that Alex’s orderly, clean, white world is a dystopia: When Alex and his white-uniformed “droogs,” disgusted, beat up a “filthy, dirty old drunkie, howling away at the filthy songs of his fathers,” we feel for the drunk, who seems quaint and harmless by comparison. Here milk signals not purity or strength but arrested development: These adolescents, we’ll soon see, have the impulse control of toddlers and the sexual and violent appetites of fiends. Their compulsive attacks, calculated to elicit the fear and pain that gives them an erotic charge, are a far cry from the avenging necessities of a whiskey-swilling outlaw.

In the S.S. Col. Hans Landa, Inglorious Basterds offers another take on the charismatic, milk-drinking psychopath who likes watching his prey squirm. We might expect the well-mannered polyglot sophisticate to prefer fine wine (think chianti in Silence of the Lambs), but in the film’s opening scene, he requests one glass and then another of fresh milk from the dairy farmer he knows to be hiding Jews beneath the floorboards. It’s the forced intimacy of the gesture that stuns—Landa demands to taste the produce of his victims, and dehumanizes them by complimenting the farmer’s cows and his beautiful daughters practically in the same breath.

Inglorious Basterds isn’t a Western, quite, but it is populated with cowboyish-rogues who act out a collective American revenge fantasy about blasting Nazi scum to bits in a thousand shootouts. In that context, it’s important that Landa be both unfathomably evil and unmistakably foreign—which is where the suspenseful milk monologues come in. With his cruel patience and manipulation, Landa proves he’s not some run-of-the-mill roughneck you might run into in a saloon, which (I guess) is why all the cartoonish, remorseless Nazi-killing is justified.

No Country for Old Men takes that kind of bafflingly disciplined super-killer and drops him back into the world of familiar Western archetypes—with, naturally, some milk added to froth up the mix. The Tommy Lee Jones character, an aging sheriff, aligns himself with the stoic Destry types of old in an opening voiceover reminiscing about his predecessors who “never even wore a gun.” Unfortunately, neither he nor the plucky but flawed cowboy antihero type (Josh Brolin as Llewellyn Moss) is any match for the villain du jour, a merciless killing machine with a bad haircut, a bolt gun, and a coin-toss fixation. Like Alex in A Clockwork Orange, Anton Chigurh (Javier Bardem) doesn’t play by anyone’s rules but his own—and his adherence to his twisted code is uncompromising. A symphony of stylized violence ensues.

Rather than give us what we want and what the genre demands—a climactic showdown between the world-weary sheriff and the chilly assassin—the plot doesn’t allow them to ever get closer than they are when they (sort of) share a bottle of milk. Chigurh takes the milk from Moss’s fridge and leaves it on a coffee table; minutes later, Sheriff Bell pours himself a glass from the same “still sweatin’” bottle. The scene is suspenseful in a he went that-a-way! sort of way, and the shot is so deliberately composed—Bell and Chigurh sit in the exact same spot and view their reflections in the exact same television!—that we know there’s supposed to be something profound in it.

But as with many of the film’s self-consciously poetic flourishes, I don’t know what the milk thing is supposed to mean, or what it’s saying about the link between the three protagonists. Maybe the Coen brothers like how dairy looks on screen (think of all those white Russians in The Big Lebowski) or maybe we’re reaching a tipping point where milk just seems to belong in violent movies.