Artie
Interesting, in a book overflowing with characters doing things that instill controversy in the book by outraging certain people, Artie has over the decades becomes the most controversial character in the book by virtue of two things he does not do. He does not have sex with Erica and he does not admit that he is gay. That he is unquestionably is coded as gay is beyond argument, but for the purpose of argument, take him at his word that his problem is not homosexuality but impotence. Ultimately, symbolically speaking, neither conclusion matters for both represent the same thing to the other characters.
Once it becomes clear to Erica that she will not be having sex with him, Artie completely disappears from the narrative until a very brief and meaningless mention at the end. The only logical interpretation of these events is that whether Artie is indeed gay or whether he actually is impotent, his presence is no longer required in cautionary tale of heterosexual passion that includes a character like Sybil. If Artie is truly impotent, he can’t possibly get Erica or anyone else pregnant because he can’t achieve erection. If Artie is gay, then he could conceivably still impregnate a woman physically, but the potential is severely reduced. So, in a weird way, Artie represents the one controversial element that apparently was considered a bridge too far by the author: any ability to engage in promiscuous sex without a genuine risk of pregnancy. And that is almost certainly the reason that Artie’s sexual preference remains ambiguous.
Sybil
Sybil is the book’s subversive character. American fiction over the previous had constructed a stereotype for the promiscuous young unmarried woman. She came from the wrong side of the tracks, she got by on looks rather than brains, she was pretty only as a result of zealous application of makeup, she built with a body that attracted all tastes in men and, most importantly, she is ultimately punished for her sexual appetite. Sybil is none of those things and so becomes a revolutionary character in the history of stories about unmarried women who just so happen to enjoy having sex. While clearly the most controversial character at the time of publication, Sybil’s infamy has faded significantly over time.
Tommy Aronson
Katherine early on complains about the pressure which her first boyfriend Tommy Aronson had placed her to have sex. The rejection of Tommy’s pressure has had the cumulative effect over time of him slowly dropping down the ladder from affection. At one time he stood on the highest rung as the boy Katherine told her younger sister she was in love with and now he is dismissively forgotten as merely a “childish infatuation.” It is Tommy and not Michael who becomes the symbolic figure of teenage romance rarely having the fuel to last forever. By the end, in fact, Michael has become merely the inbetweener down there with Tommy as they both wait patiently for Theo to join them.
Erica
Erica is the narrator’s best friend and desperately wants to become Artie’s sexually active girlfriend. He keeps putting off putting out, however, and within that single reversal of expectations of phrasing can be located Erica’s symbolic status. Erica is the symbol of the new postmodern double-standard. That phrase used to refer to how boys were expected to sleep around, but girls who did so were considered immoral. Erica’s actions toward Artie reveal a new double standard: it is bad for Tommy to pressure Katherine to have sex, but when Erica pressures Artie to do so, she is trying to help him discover the joys of heterosexuality.
Theo
Theo is a surprisingly complex symbolic figure. On the one hand, he represents the real world that inevitably threatens teenage fantasies of romances lasting much beyond high school much less forever. At the same time, however, Theo also becomes a symbol that somewhat undercuts the image of Katherine as a responsible manager of her biological urges. Katherine finally loses her virginity on the basis of a genuine belief that she and Michael will be together forever and it is this which distinguishes her both Erica and Sybil. Her rather shockingly easy transition into the arms of Theo rips her right out of that responsible image in a way that begins to move her closer toward promiscuity. Theo’s secondary symbolic status is far less ennobling: he becomes Katherine’s recognition that the world is full of guys to become sexually active with even without the promise of forever attached.