A new study has found that even though people may report that their sexual orientation has changed over time, their genital arousal to different types of sexual stimuli (i.e., erotic videos) tends to remain the same. It is possible that people overestimate changes in sexual orientation, since these changes are not reflected in physiological sexual response. The study was published in the Journal of Sex Research.
Sexual orientation is an enduring pattern of romantic or sexual attraction. Most people are attracted to persons of the opposite sex (heterosexual orientation), but people can also be attracted to individuals of the same sex (homosexual orientation) or to both sexes (bisexual orientation).
Sexual orientation is most often considered to be stable. Support for this comes from studies of males who had their genitals removed surgically due to a rare medical condition that required such intervention and who were raised as females. Despite these changes and upbringing, the vast majority of these individuals later identified as males and were attracted to females.
Additionally, conversion therapies — treatments that make deliberate efforts to change sexual orientation in adulthood — show little evidence that such a change is possible and appear to be associated with significant harms.
On the other hand, some longitudinal studies suggest that sexual orientation can change over time in men and women. However, such studies are typically based on self-reports and thus subject to biased responding. These studies also found women to be a bit more likely to report a change in their sexual orientation than man. Individuals with bisexual orientation were found to be more likely to change their sexual orientation than persons attracted to just one sex.
Study author Dragos C. Gruia and his colleagues wanted to more closely examine the stability and proneness to change of sexual orientation by taking into account physiological evidence and not only self-reports. Their expectation was that any changes in sexual orientation must also be reflected in sexual arousal patterns, at least in men.
“In theory, if self-reported sexual orientation changes, sexual arousal should undergo a corresponding change,” the study authors explained.
Participants were 53 men and 72 women, around 24-25 years on average, predominantly White. They were first asked to report their sexual orientation identity and sexual attraction. Sexual orientation identity almost completely corresponded with the sex(es) one is attracted to.
Participants were then taken to a private booth where they were shown 6 sexually explicit videos. The purpose of showing these videos was to incite sexual arousal and obtain information on which videos produced it. 3 videos were featuring a man and 3 were featuring a woman. Videos lasted 3 minutes each and showed the actor masturbating in a bedroom.
The selected videos were the most highly rated videos from a collection of 200 pornographic clips that were evaluated in a previous pilot study. Before and after each sexually explicit video, participants were shown 2-minute clips of nature scenes that were meant to return them to a non-aroused state.
Researchers collected data about genital arousal of participants while watching videos using a strain gauge measuring changes in the circumference of the penis in men. Women’s genital arousal was assessed via changes in vaginal pulse amplitude using a device called a vaginal photoplethysmograph. Before the videos started, male participants were asked to place the strain gauge halfway along their penis. Women were asked to insert the photoplethysmographs into their vaginas.
Participants went through this procedure twice. The study authors aimed to have them repeat the procedure exactly a year later, but due to various reasons this could not be done for all students. On average, students repeated the procedure 15 months later, but some students repeated it up to 3 year later.
Results showed that, between the two data collection sessions, 5 men and 13 women changed their self-reported sexual orientation group. All 5 male participants that changed sexual orientation were persons previously identifying themselves as bisexuals. In women, 5 out of 18 bisexual individuals reported a change in sexual orientation.
The same happened in 6 out of 31 heterosexual and 2 out of 18 homosexual participants. These results supported the findings of previous studies that sexual orientation is relatively stable (most participants did not change their orientation) and that women are more prone to changing their orientation than men (around 20% of women in the study changed orientation, compared to around 10% of men).
Sexual arousal was generally in line with reported sexual orientations. Sexual arousal of men was more in line with their self-reported sexual orientation than sexual arousal of women. In bisexual men and women, sexual arousal to sexually explicit videos was less in line with their reported sexual orientation than in hetero- and homosexual men and women.
Finally, the direction of change in sexual orientation was not associated with the direction of change in sexual arousal. This finding was the same for men and women and for all sexual orientations. Contrary to the expectation of study authors, when participants reported a change in sexual orientation, this was not associated with corresponding changes in the pattern of sexual arousal to sexually explicit videos.
“There are several ways in which we can interpret the lack of change in arousal: One interpretation is that the assessment of physiological sexual arousal is subject to more measurement error than self-reports, which could weaken any true patterns in arousal (i.e., correlation, mean change),” the researchers wrote.
“An alternative interpretation is that longitudinal patterns observed in self-reports provide an over-estimation of the actual change in self-reported sexual orientation. This is not to say that change in sexual orientation does not exist, but rather that change may be rarer than suggested by self-report. Finally, it may be that change in self-reported sexual orientation truly happens subjectively but is not reflected by any corresponding change in physiological responses.”
The study makes an important contribution to the study of sexuality. However, it also has limitations that need to be taken into account. Notably, it is possible that there were too few participants who exhibited a change in sexual arousal or orientation to detect any reliable patterns. Additionally, because of the intrusive nature of the measurement procedures, it is possible that the study suffered from a self-selection bias and that results on a sample more representative of the general population might not be equal.
The study, “Stability and Change in Sexual Orientation and Genital Arousal over Time”, was authored by Dragos C. Gruia, Luke Holmes, Jaime Raines, Erlend Slettevold, Tuesday M. Watts-Overall, and Gerulf Rieger.
