The frathouse comedy is almost as much of an all-American institution as fraternities themselves. In 1978, National Lampoon’s Animal House became one of the most profitable movies of all time and Hollywood realised that there was gold in them there locker rooms. Animal House’s uproariously wacky tone, however, couldn’t have been further removed from Goat, the dark drama starring Nick Jonas about a fraternity’s brutal hazing ritual. Out in the US this Friday, it’s an indication of how America’s attitude has changed towards fraternities, from harmless hijinks to something much more sinister.

After Animal House grossed $141m, having been made on a $3m budget, cinemagoers couldn’t move for snobs and slobs battling in subgenres from sports comedies (Caddyshack, Ski School) and high school raunchfests (Porky’s, Fast Times at Ridgemont High). The venues may have varied, but the central elements remained the same: a group of lovable, sex-crazed guys doing battle with cruel authority figures or talented rivals – and somewhere along the way, of course, they score with some chicks.

Emerging from the post-Watergate era in which suspicion of the establishment was at an all-time high, Animal House and 1984’s Revenge of the Nerds had a strong whiff of anti-authoritarianism. There was one aspect that was wearyingly traditional, however: the movies’ depiction of women as little more than disposable objects to be fought over and won by the guys. But as the genre evolved, so did its sexual politics. Watching fraternity comedies over the past few decades we see a slow march towards gender equality and a deconstruction of the patriarchy both onscreen and off.

Animal House: just lovable, sex-crazed guys doing battle with authority. Photograph: Allstar/Universal/Sportsphoto Ltd

On its release, the misogyny of Animal House seemed to pass critics by. In his four-star review, Roger Ebert praised it as “an end run around Hollywood’s traditional notions of comedy”. He praised the fraternity’s womanizing leader Otter (Tim Matheson) for achieving “a kind of grace in his obsession”. This is the womanizer who seduces the dean’s wife to get even and, in one of the funniest sequences, poses as a dead girl’s unwitting fiance in order to garner sympathy from the deceased’s attractive roommate.

More disturbing is the attitude displayed by Larry (Tom Hulce) towards a young, attractive cashier. He invites her to a party at the frathouse, where she promptly passes out topless in his room. A devil and angel appear on Larry’s shoulders, as he grapples with the idea of raping her unconscious body. Eventually, he does the right thing, and seems proud of it. But later, he takes her out again. With both of them sober, they’re about to have sex, when she reveals that she’s only 13. The scene cuts away, but it is later revealed that Larry had sex with her anyway.

What’s particularly toxic about this scenario is that unlike Otter, Larry is one of the good guys. Larry is a virgin, and the fraternity – which Animal House holds up as an antidote to the oppressive establishment – turns him into a statutory rapist. At the time however, no one seemed notice. Even Pauline Kael celebrated the film, writing in her review: “I stand with the slobs.”

Jock stars: Ted McGinley and Julia Montgomery in Revenge of the Nerds. Photograph: Cine Text/Sportsphoto Ltd/Allstar

Revenge of the Nerds, the next frat movie to hit big at the box office, is similarly icky. Like Animal House, it focuses on a crew of students rejected from the establishment fraternities who form their own frat and eventually do battle with the jocks. In Nerds, the heroes aren’t dumb drunks, but their goal of abusing women to validate their own manhood remains the same.

In the film’s climactic scene, Lewis (Robert Carradine), the chief nerd, poses as a jock to have sex with his unwitting girlfriend. The law calls this rape, but the film simply sees it as a victory for the nerds. Meanwhile, his friends are across campus selling nude photos of her that they took without her consent in an effort to win a competition with the jocks. In these films, the characters are so concerned with their status in the eyes of other men that the treatment of their female peers is totally irrelevant.

As times change, however, so do attitudes. Steve Zacharias, the writer of Revenge of the Nerds, expressed contrition about his work. “That was rape,” he said, referring to the climactic scene. “If I knew now what I knew then, I wouldn’t have done that.” He also apologized for the plotline involving stolen photographs, even connecting it to the criminal spying of ESPN broadcaster Erin Andrews that made national news over two decades later. “A lot of times the media introduces terrible concepts ... that puts thoughts into people’s minds,” he said.

Neighbors 2: Sorority Rising criticises the fraternity from the inside out. Photograph: Allstar/Universal Pictures

Over the years, the fraternity movie has popped up from time to time in its original form – Old School (2003) featured jokes about statutory rape and topless wrestling – but it also gave way to a new kind of fraternity movie that gave voice to characters and ideas that were previously marginalized. The House Bunny (2008) was the first sorority movie not to use its female characters solely as titillation for a male audience. Stomp the Yard (2007) was a rare instance of a film focusing on black fraternities, almost 20 years after Spike Lee’s School Daze (1988).

The fraternity movie has certainly changed with the times, but this year, the transformation came all at once. Bad Neighbors 2: Sorority Rising and Goat, which opens in the US on Friday, criticize the fraternity system from the inside out. The original Bad Neighbors (2014) viewed fraternities sympathetically, but it offered a mild criticism. One of the film’s most surprising scenes comes between Teddy (Zac Efron) and Pete (Dave Franco), college seniors and officers of the party-heavy frat. When Teddy confronts Pete about devoting more time to his studies and job interviews than partying, Pete makes clear that he doesn’t buy into the mythology of brotherhood that has underpinned every fraternity movie in existence. “You know none of this matters, right?” he tells him.

This year’s sequel, Bad Neighbors 2: Sorority Rising, goes even further to subvert the toxic masculinity of the genre. The film opens with Pete getting engaged to another man and sharing the moment with his former brothers. Teddy (Zac Efron), the alpha-male rush leader who once represented the social conservatism of the Reagan era, approves and is happy for his friend. These films were never explicitly homophobic – the villain of Animal House called his pledges “faggot”, but the heroes never did – but an embrace of queerness within the fraternity system still stands as a bold embrace of progressive social mores.

The film’s real social victory is in its feminist qualities. One storyline follows Shelby (Chloë Grace Moretz), a freshman who starts her own sorority when she learns that, by Greek rule, sororities are not allowed to host parties – which is true. Teddy even offers his help to mentor and tutor the young women, never once treating them as sexual objects. The film subverts genre tropes, and takes the opportunity to explore the sexism that is, the film argues, inherent in the Greek system.

Hazing horror: Ben Schnetzer and Nick Jonas in Goat. Photograph: Supplied

Bad Neighbors 2 is optimistic that fraternities can change, but Goat offers nothing so rosy. The film, based on a memoir by Brad Land, depicts the brutal horrors of hazing at real-life fraternity Sigma Phi. It’s a long way from Animal House, whose version of hazing was getting doused in beer or, at its worst, being paddled in a perverted but relatively innocuous ritual. Goat lifts the veil and shows that, while the fraternity movie itself may have evolved, activities at real-life fraternities have only gotten worse.

The pledges in Goat are urinated on and made to sleep in cages. They are forced to drink far more excessively than anything we’ve seen before in a frathouse film – and consume entire bottles of hot sauce. In the scene that gives the movie its title, a small group of pledges are instructed to drink an entire keg of beer – and if they fail, they will be forced to have sex with a goat. Shocking as these images are, the film would come across as ineffective moral scolding if it were not seen through the eyes of its protagonist, who is mercilessly beaten by a pair of strangers in the film’s first scene, and spends the rest of the film – especially Hell Week, the hazing period covered in the film – trying to prove to himself and the world he’s not a coward.

In Goat, there is no overbearing dean or rival fraternity with whom the heroes do battle. The villains are the frat leaders themselves. Earlier films would have Brad break off and start another fraternity – a kindler, gentle one – but Goat keeps its sheep among the wolves, trapped in the institutionalized violence that have defined both fraternities and their cinematic representations since day one.

Ultimately, fraternities have become a stand-in for the American establishment itself. In the late 2000s, as Americans were expressing their disappointment over the Bush presidency, movies like The Good Shepherd and Oliver Stone’s W equated the fraternity system – specifically, the real-life Skull and Bones secret society at Yale – with the political establishment. This year, with voters offscreen expressing new levels of antipathy towards that establishment, pop culture seems to be following suit. While the fraternity movie may never be completely upended, history shows that progress can sometimes be made from within.