In this essay I said:
When people voice the familiar cliché, “X is old enough to be your [parental unit],” it’s not because they literally fear that every May-September liaison will result in corporeal incest. Rather, aversion to such liaisons seems more rooted in a quasi-religious sense of the proper order of life: young with young, old with old. These are just two examples of what I term “incorporeal incest.”
The terms "corporeal incest" and "incorporeal incest" are henceforth subsumed by the term "clansgression," implying, for fiction, a narrative action that confuses the proper hierarchies of familial and quasi-familial relations.
For some time I've contemplated the consequences of this statement. I still hold to the idea that May-September heterosexual pairings may recapitulate strong "daughter-father" or "son-mother" connotations. But does that necessarily mean that pairings between heterosexuals of roughly the same age are inevitably closer to the model of "right relations"-- even if, with Bataille, one believes that even the closest that humans can get to that model is still transgressive in nature?
The obvious answer is that it ain't necessarily so. Even age-appropriate status between two given subjects does not nullify the possibilities for clansgressive activity. One can find some suggestion of the potential for the symbolic reading of "sister-brother" clansgression in the familiar joke: "If all men were brothers, would you let one marry your sister?" The joke is primarily a play on the different connotations of the word "brother," but its logic is irrefutable: if all males and females were siblings, sibling incest would be the only way to reproduce the human race.
However, even in real-life culture the spectre of clansgression can appear with respect to age-appropriate pairings, even when the subjects involved are not physically related, nor are they raised in circumstances of regular propinquity (cf. "neighbor-kids who grow up together.") In fiction this motif is most frequently seen in the trope "high school girl dates college boy," or (more rarely) the reverse situation with respect to gender assignment. Typically no more than four years separates the collegian from the high-schooler, so it isn't feasible for such pairings to carry the "May-September" vibe. Yet the sense of boundaries traversed is clansgressive, usually because it's assumed that one member of the couple has already had sex and will be initiating the other. The motif appears prominently in the 2010 film EASY A, in which high-school protagonist Olive, tired of having a friend bug her about her virginal status, makes up a story about losing her cherry to an unnamed college student. Making her imagined seducer a college student suits Olive's purposes of anonymity, so that no one at her school will contradict her tale, but every high-school student immediately finds it credible that a collegian makes a likely enough seducer. It's an interesting detail that in Olive's fabricated tale, the person who introduces her to her seducer is none other than her college-age brother, a character who does not appear in the film, any more than does the collegiate suitor.
Earlier I mentioned the motif of propinquity with respect to the backstory of Reed and Sue of the Fantastic Four. That narrarive isn't the best illustration of the motif, though, for the circumstances of Reed and Sue's meeting are delivered as an explanatory toss-off in the original Lee-Kirby comics. In general those stories tried as hard as they could not to acknowledge a significant age-difference between Sue (young enough to have a teenaged brother) and Reed (old enough to have served in World War II). A better illustration of clansgressive propinquity might be Ken Akamatsu's LOVE HINA.
The set-up for LOVE HINA is that nebbishy loser Keitaro Urashima finds himself managing a girls' dormitory for middle school and college-bound high-school students. Naturally, in the long-running tradition of harem comedies, the girls are winsomely cute, and eventually all of them become enamored on some level with Keitaro, the only male living with them. A modicum of adult supervision is provided by Keitaro's aunt Haruka (the dark-haired woman at far left), but most of the time the girls are free to tease and torment Keitaro, who gets no points for being a little older than the oldest of them, since he's failed his college-entrance exams three times at the series' beginning. The clansgressive vibe generated by the series eventually develops along the lines of an older "brother" being forced to put up with the hijinks of a band of capricious "sisters," all of whom take on a sibling-vibe partly because they share a house, with special emphasis on the arrangement of Keitaro's room being located directly beneath that of Naru Narusegawa (the girl at extreme right holding Keitaro's arm). Naru, it will eventually be revealed, has a connection to Keitaro than neither of them remembers when they meet, for they were the children of neighboring parents-- a connection that plays a large part in the development of their romance.
The young girls seen on Keitaro's left-- wacky Kaolla, shy middle-schooler Shinobu, aggressive Kitsune, and diffident Motoko-- are also not really related to Keitaro, any more than Naru is. However, they relate to Keitaro in ways that suggest sibling kinship. Even though Keitaro is older than the oldest girl, Kitsune, she gives the impression of having had sexual experience whereas Keitaro has none, which may be the reason why she chooses to call him her "younger brother." Shinobu, who like Kitsune has no siblings that are mentioned, relates to Keitaro like an older brother, though at the same time she has a mild crush on him, which brings down on Keitaro the righteous wrath of Naru, as she accuses him of trying to get jiggy with a middle-schooler. Motoko's backstory involves her convoluted relationship with her sister, a relationship that may have involved Motoko coveting her sister's never-seen husband, who is Motoko's brother-in-law. Finally, Kaolla frequently stresses that Keitaro reminds her of her brother-- also never seen in the manga series-- and though she too is a middle-schooler who would be age-inappropriate for Keitaro, Kaolla possesses a magical ability to "age" herself temporarily, so that she can become closer in age to the beleaguered dorm-manager.
None of these sibling-constellations would be remarkable by themselves, but it seems quite significant that brother-relationships are the only ones mentioned for all of the girls. This almost excludes Keitaro's aunt Haruka, but then, because she shares Keitaro's last name, she can only be the unmarried sister of Keitaro's never-seen father-- so even she is partly defined by a brother-relationship. Keitaro's parents, and those of the young women, are referenced obliquely if at all, with only Haruka and her sometime lover Seta providing adult input-- but they're essentially the "fun aunt" and "fun uncle" who don't interfere with any of the adolescent hijinks. The lack of parental influence might indicate that LOVE HINA actually is a "world of siblings," devoted to almost every conceivable take on sister-brother clansgressive relations, except for relations between biological siblings.
Late in the series Akamatsu introduces Kanako Urashima, who is Keitaro's adoptive sister, but she's even more aggressive than Kitsune, for she earnestly plans to seduce Keitaro. Keitaro is not willing, since he does think of her as the same as a biological sister, but given that LOVE HINA is a comedy, his consent is not important. What is important is that Naru, the romantic front-runner in the Keitaro Derby, is finally forced to put her affections on the line to prevent a forbidden level of clansgressive activity-- though as noted earlier, Naru herself is implicated in the sibling-clansgression vibe by virtue of her childhood association with Keitaro.
Having shown that sibling relationships can be potentially just as clansgressive as those between "age-inappropriate" subjects, in PART 3 I'll move on to the subject of a form of sibling relationship that manages to be exogamous and endogamous at the same time.