Based on the play of the same name, writer and director Leslye Headland's film 'Bachelorette' tells the story of three messy-headed bridesmaids on the day leading up to the wedding of a friend from high school they used to call "Pigface."

But beneath all the superficial cattiness, drugs, and booze there lies a harsh reality for each of these women.

If we placed female-driven comedies on an evolutionary chart, 'Bachelorette' would be the missing link between 'Bridesmaids' and 'Young Adult.' The wedding plot evokes comparisons to the former, but the tone and the personalities of the film's leading ladies is more in keeping with the latter. Katie (Isla Fischer), Regan (Kirsten Dunst), and Jenna (Lizzy Caplan) are each willfully regressive in their own ways. Katie is the ditz, Regan is the type-A jerk, and Jenna is the drug-addled wreck. They've all gathered to support their friend Becky (Rebel Wilson) on her wedding day, and although the trio have always made fun of her behind her back, they feel committed to being "good friends."

But why?

Remarks about Becky's weight and how someone like Regan should have obviously been the first one to get married seem to indicate that these women share a friendship that isn't genuine, but as 'Bachelorette' progresses, the film becomes less of a raunchy comedy and more of an examination of why these women are the way that they are -- and we begin to understand what makes them friends. Headland doesn't seek to have them redeem themselves with grand gestures and unearned moments of clarity. Instead, she allows her characters to exist as the people they are, hideous warts and all, and asks us to understand them and the choices that inform who they are. We are not asked to forgive or encourage, but perhaps empathize or accept.

To be fair, there's a certain element of disappointment when many of these key revelatory moments feature men as the catalyst. Instead of giving these women eye-opening moments among themselves, it seems to take the intervention of a man to strike them with a revelation. This small complaint aside, the women go from icy entities with whom we cannot relate (but rather take joy in their epic screw-ups and delightfully rotten attitudes) to empathetic human beings -- mirror images of the worst parts of ourselves.

Like Charlize Theron's Mavis in 'Young Adult,' the reason many will refuse to identify with the characters in 'Bachelorette' is that no one wants to admit that they could. When you start to ask yourself why someone like Regan would help Becky, the pieces seem to fall into place. Regan's well-rehearsed lines about the meaning of working in a hospital with cancer-ridden children aren't so much a put-on to make herself appear more kind, as they are the indication of her desire for perfection. This becomes even more clear when it's revealed that she is/was a bulimic, a disease that affects women who need to feel in control and have an obsession with being perfect. Over one-half of teenage girls report using unhealthy methods to lose weight, and 25% of college-aged women report bulimic behavior. When you take these statistics into account, it's harder to pass judgment on Regan's character, but even if you've never personally had an eating disorder, her behavior is still relatable, considering the effect media has on young women and their self-image. This is summed up when Regan is later asked why she would make herself throw up, and she simply responds, "I wanted to be beautiful."

Regan's well-rehearsed lines, her strict scheduling, her obsessive-compulsive desire for perfection -- all of these things indicate someone who just wants to be a good person and is trying desperately.

Katie, on the other hand, is more of the stereotypical airhead who turns out to be a little smarter than she initially lets on. But her real problem is that she learned early that sex is what you do when you like someone, and her partying isn't so much about having fun as it is about enabling herself to open up to others. She's the type of girl who has always had it easy, with boys letting her copy their homework, but that kind of stuff isn't something to scoff at and say, "Oh, look how easy she's had it! Being pretty must be so hard!" The point with Katie's character isn't so much her appearance as it is her personality. She's just never known any better, and her high school habits carried over into adulthood, where she now works in retail and wants a boyfriend with a job, something that alludes to her desire to be more responsible.

But Jenna is probably the worst one of them all. A lazy, meandering woman with no apparent ambition and a proclivity for cocaine, Jenna is callous and emotionally remote. Her real motivation for attending the wedding is to see her high school boyfriend -- the guy that broke her heart and ruined her life. It seems cliche and ripe for typical, soulless antics until the real reason why she resents Clyde (Adam Scott) is revealed abruptly during a scene on the subway. Jenna's inability to let the past go and the way she seems frozen in that time of her life with her continued drug use and apathy suddenly crystallizes. She never felt that Clyde really made an effort, so why should she? If the one person -- besides herself -- that should have cared couldn't bring himself to, then what point is there? What worth does she have?

Becky isn't without her flaws, either. She's emotionally sensitive and overreacts to everything, but she can also be just as bitchy and demanding as her friends. In the third act and on the morning of her wedding, the slightest hint that things might not go her way unleashes a hilarious fury. During a moment with Regan, the two reminisce about high school and how Becky covered up for Regan's bulimia, and everyone teased Becky for being fat and not competent enough to lose weight like a normal person. In the most touching scene of the film, Regan recalls the simple, crass advice she gave to Becky then: "F--- everyone."

The poor behavior from Katie, Jenna, and Regan is partially because they're stuck in their high school mindsets for their own specific reasons, but also because they envy Becky for having a normal fiance and growing up, and one of the hallmarks of growing up is putting on a beautiful dress and settling down with someone who loves you and accepts you. Becky's fiance accepts her, but Katie, Jenna, and Regan want so badly for someone to see past their bulls--- and accept them, too. The real discovery comes when they begin to ask themselves why Becky is getting married first, but the real discovery for the audience lies in the question: why do they care about Becky?

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