In her essay on the culture and work of slash fiction, Constance Penley analyzes the slasher's depictions of the relationship between Captain James T. Kirk and Commander Spock of the orginal Star Trek series. She suggests that this specific relationship is used so frequently because it presents readers with a radical reformation of gender roles; Kirk and Spock, as male friends and distinguished officers in the Star Fleet, experience equality that fans of the series apparently believe cannot exist in a heterosexual relationship. Penley says, "Where there is mutuality of gender there is, at least in theory, a degree of equal interchange and individuality that is often automatically negated in the conventional [heterosexual] marital union."
Penley elaborates upon this idea by suggesting that slasher fans of the series, themselves mostly heterosexual, believe that male gender roles could feasibly change between the 1960s and the twenty-third century to the point that Kirk and Spock could be in a sexual relationship without it affecting their status as officers or friends. Indeed, there are hints toward this sort of relationship between them in episodes like "Amok Time," in which Kirk refuses to reprimand Spock for his moments of passionate insubordination brought about by his impending state of Pon Farr. At the end of the episode, Spock shouts with excitement at the realization that Kirk has not died and admits that his interest in his "wife" on Vulcan completely disappeared with the thought of losing Kirk.
This situation is particularly odd in terms of the gender dynamic that Penley describes. While Kirk and Spock take on masculine roles in the episode "Amok Time," Spock explicitly states that he is "not a man." While he means that he is not a human, that his Vulcan nature makes him essentially different than a human, the choice of the word "man" is striking. He seems to suggest, in his moment of impassioned weakness, that he is not a man compared to Kirk, as though their relationship is in that moment more hierarchical than at other times. If for only a moment, Kirk and Spock fall into a sort of heteronormative relationship with a slash twist. I feel that this highlights a logical break in the thinking of the slasher fans as posited by Penley: if masculine gender roles could shift to such a degree in 300 years, why could feminine roles and heterosexual relationships not evolve in a similar manner? This seems like a particular odd idea to ignore in this context, given that Star Trek emerged in the same decade as the feminist movement that fostered writers like Le Guin and Tiptree and that the roles of women in society and relationships was already in the midst of unprecedented changes.