The most popular theory as to what the film is about is that it is a social satire, critiquing the hedonistic and self-obsessed New York of the late 1980s. As outlined above, the society depicted in the film is one of no real interpersonal relationships, no empathy, a society made up of people who care only about themselves and their own ability to accrue massive amounts of wealth and materialistic trophies; the richer you are the better you are. If someone has a nicer apartment than you, it is a cause for concern, if someone has a nicer business card than you, it is a cause for jealousy. In this decadent society, virtually everything functions as a status symbol; people have no real inner psychological awareness, they measure themselves on their external appearance, and they measure one another based upon what they see on the surface; the more elaborate the surface, the more successful the person. Simplicity suggests nothing but failure, if you don't wear an expensive suit, it means you can't afford one and are therefore inferior to those who can. None of the characters in the film would stop to think for a moment that perhaps someone may not be wearing an expensive suit because they don't want to. This kind of thinking simply doesn't enter into the equation in their society; a society of excess, greed, self-absorption and isolation.
This theme is perhaps more obvious in the novel. For example, the constant listing of the items of clothing worn by each and every character (this is mirrored in the film in Bateman's meticulous listing of his shower products). Another good example is a conversation between Bateman and Carruthers concerning Carruthers' recent dinner with a client. The client had roasted chicken, and neither Bateman nor Carruthers can understand the fact that the dinner came with no sauces or accessories. Completely incapable of grasping the idea of someone eating a normal chicken for dinner. At one point, an extremely confused Bateman asks, "What shape was it cut into?" (107). A further example is when Bateman reluctantly attends a U2 concert with Evelyn. Complaining about everything, Bateman points out that "The only real pleasure I get from being here is seeing Scott and Ann Smiley ten rows behind us, in shitier, though probably not less expensive seats?" (107). Bateman's seats are better, therefore, he has 'won' the unspoken contest between them, and his superiority is something to be celebrated.
Regarding the film, the filmmakers themselves have offered various theories as to what the true meaning may be, and a good way to engage with the possibilities as to meaning is to look at what some of them have said about their own interpretations of the work, as well as the interpretations of critics and scholars. This selection of quotations offers a broad cross section of such opinions:
Official site: "The unfolding cinematic fable suggests a series of themes about the 1980s: the obsession with outer perfection, even when it masks inner emptiness; the amoral insistence on conformity at all costs; the desire for stimulation that keeps raising the threshold higher -- more drugs, money, sex, sound, color, action; and the emotional isolation, expressed by Bateman's videotape addiction, and the fact that he has no back-story, no family, no real characteristics apart from the labels on his clothes" (official site archived here).
Guinevere Turner: "This is a story about men living in a man's world, competing with each other over who has a better tan, who has better clothes. Nobody can tell each other apart, it's all very empty, it's shallow, it's competitive, and it makes men look really really bad, and it makes them look kind of gay, because it is such a mans' world, and they are so obsessed with how they look, with clothes and their business cards, that it's taking that competitiveness to an aesthetic level that's kind of what we think of as how gay men are; impeccable dressed, impeccably groomed, really concerned with each other, and women are an outside factor. And it's funny, it's making fun of that, and I find that to be so powerful in the book, it's just outright mockery of male behavior" (from DVD commentary track).
Mary Harron: "The book and the film are often defined as being about the 1980s, but the 1980s did not invent greed, did not invent commodity fetishism, did not invent a society that is so obsessed with perfect surface" (from DVD commentary track).
Bret Easton Ellis "Like the novel, the movie is essentially plotless, a horror-comedy with a thin narrative built up of satirical riffs about greed, status and the business values of the 1980s culture" (official site archived here).
Guinevere Turner: "It's part of the idea of the character, that everything is so empty, although he has tons of money and he's constantly buying things and obsessing over having the thing, he's trying to fill this void, and it's not working. Part of filling that void is trying to keep up with the Joneses, so to speak. He's desperately trying to stand out as an individual, which is arguably why he's killing people, and he can't get noticed. It's all part of trying to feed this void that is, in a larger sense, the void of the eighties' intense consumer culture and decadence" (from DVD commentary track).
Bret Easton Ellis: "Mary Harron's American Psycho is set mostly in pre-crash 1987 but it's a period that almost seems as distant as the Jazz Age or the swinging 1960s London of Austin Powers. The Armani-clad automatons that populate American Psycho go-go 1980s Wall Street wasteland don't realize how much their world sucks (they're like children playing at being lonesome grown-ups) but the movie zones in on Patrick Bateman - one of those anonymous drones - who does, and it details the numbing ritual of his bored, deranged young businessman's daily life. Lost in his psychosis we see him in his empty office watching "Jeopardy!" or listening to Kenny G on his Walkman; on his dates; during his exercise regime to perfect a lean sculpted body; the occasional murder he commits; his facials; dining out with colleagues; watching horror and porn videos; and constantly looking at himself in mirrors (even during sex), which of course, reveals nothing, and the movie - presented in gleaming wide-screen - is a visual representation of his mindset: sleek, cold, airless, a world where everything is ultimately about style. (The production designer Gideon Ponte, deserves special mention for the awesome, glamorous sterility of Bateman's bachelor pad.) But there is also the suggestion (as in Fight Club) that Bateman's escaping from his life by re-imagining it, which is the only way for him to assert control. And it hints that his "acts" are caused by his reaction to the emptiness and foolishness of his surroundings which inspire his defiance, as well as his inability to hold back his darker impulses, and that the killings and destruction are his only means of aiming for truth" (official site archived here).
Guinevere Turner: "It's almost like we watch Patrick Bateman go from his normal life. We see a mounting anxiety in him of being mistaken for other people, of killing people and not getting caught, like the real estate agent. And we get to the scene where he's crying on the phone and confessing to his lawyer what he did, and then his lawyer doesn't even really know who he is. The idea being that he gets so hysterical he's just straight up begging somebody to listen to him confessing to all these crimes, and there's still no reaction, and it's almost like he gives up. And he's right back where he started; he' sitting in the same bar with the same stupid friends talking about what they're going to eat and what they're going to drink, and it's just like, this guy is out there, and there's lots of other guys like him. It's almost like alienation breeds serial killers, everyone's so disconnected, it really doesn't matter, it doesn't matter who you kill, it doesn't matter what you do. We're all just robots. And to me you're supposed to be left with a feeling of emptiness, like fear, nothingness, no one's paying attention, nothing matters" (from DVD commentary track).
Bret Easton Ellis "the film clarified the themes of the novel. It clarified that the novel was a critique of male behavior" (Charlie Rose interview)
Guinevere Turner: "We're not just having a gay old time showing women be killed by a serial killer, we're showing you a character and his panic. He's in permanent panic about where he fits in, whether or not he's cool enough. We're just making so much fun of him. He and his male contemporaries are so weak, so shallow; no one looks good, the women don't look good, the men don't look good, no one looks good. Everyone's completely corrupt and pretty disgusting. The arc that the character has had from the beginning to the end of the movie is that he has become acutely aware of what it is, and he can articulate it to himself; he's in pain and he wants to inflict that pain on everyone, he feels nothing, he doesn't care that people are in pain. But the most important thing he says is that there's no catharsis, and that's what we come to expect conventionally from character and character development; they come to this point and they're changed forever, they are no longer the person that we met, but the disturbing thing about this story, and the way we intended it is that we start just where we left off. It's almost more disturbing now because he knows; he's more aware of what he's doing and he's going to keep doing it anyway. He wanted catharsis, he wanted to get caught, he wanted to have his life changed; to be thrown in jail, to be killed by someone himself, but he just can't, so it's kind of like, he's a mutant; nothing can kill him so he just got that much more detached. Now he knows, and it seems like he's going to act on the fact, that he can do anything; he can kill people and people are going to say they had lunch with him yesterday. Nothing matters, no one's paying attention, and so he might as well, since the only thing that he seems to feel real about or get excited about is killing people, so he might as well keep doing it; it doesn't matter, no one is going to notice. And that's very disturbing" (from DVD commentary track).
Gavin Smith (editor of Film Comment): "You can see the film as an extreme comedy of manners, because so much of it is about social status, how people interact, social one upmanship and social anxiety, and a great deal of it is about these transactions that go on between businessmen or between men and women in a rather elevated kind of social world that's removed from day to day reality [...] In a way, it's the introduction of the horror element or the element of the serial killer violence into a gentile, polite world, where whatever the underlying sentiments that people have to one another, which, very true to Reaganism, is very cut throat underneath, that's something that there's a real tradition in social satire going back to Molière; there's always the surface politeness and the surface manners and grace, and underneath, the primary kind of human urges, which are usually sexual. Here, money and sex are interchangeable in a certain kind of way of looking at the 80s, in which money was the erotic object, it was the source of eroticism in the 80s" (quoted from "American Psycho: From Book to Screen").
Bret Easton Ellis: "The film is a pitch-black comedy of manners about male narcissism" (official site archived here)
David Ansen (critic): "The movie dissects the '80s culture of materialism, narcissism and greed" (quoted here).
Owen Gleiberman (critic): "Harron, if anything, is an even more devious provocateur than Ellis was. By treating the book as raw material for an exuberantly perverse exercise in '80s nostalgia, she recasts the go-go years as a template for the casually brainwashing-consumer/fashion/image culture that emerged from them. She has made a movie that is really a parable of today" (quoted here).
Richard Corliss (critic): "Harron and co-screenwriter Guinevere Turner do understand the book, and they want their film to be understood as a period comedy of manners" (official site archived here).
bloody-disgusting.com: "The film reflects our own narcissism, and the shallow American culture it was spawned from" (quoted here).
Mary Harron: "I think American Psycho is very feminist. It's easy to believe that because the character is a misogynist, the story is too. But, it was obvious to me there was something going on beneath the horror. For instance, the book shows how the excesses of the 1980s were manifested in warped relations, not only between men and women but also among men. That's where a lot of the humor lies, in poking fun at these peacocks who are so strangely preoccupied with one another. It ends up being an indictment of machismo and misogyny" (official site archived here).