Participants ranked the films in order of how aroused they felt watching them. The heterosexual women in the study ranked male-male films the lowest, followed by female-female in the middle, and finally female-male films the highest. But when the genital arousal data were compared to these rankings, something interesting emerged.
It turned out that the physical data told a completely different story. Subjects claimed male-male porn interested them the least, but looking at the physical response, male-male and female-female films ranked similarly – both high. On paper, straight women ranked heterosexual pairings the most arousing, but their response while watching these films was actually lower than the other films.
This article didn’t really touch upon societal expectations that may explain why heterosexual women stated that heterosexual porn scenes were the most arousing, when arousal data measured inside of their bodies showed that both other types of porn, female/female and male/male, created a higher sexual response.