We found that change in self-reported sexual orientation was not reflected in genital arousal, providing tentative support for the notion that self-reports may overestimate change in sexual orientation

Stability and Change in Sexual Orientation and Genital Arousal over Time. Dragos C. Gruia, Luke Holmes, Jaime Raines, Erlend Slettevold, Tuesday M. Watts-Overall & Gerulf Rieger. The Journal of Sex Research, Apr 12 2022. https://doi.org/10.1080/00224499.2022.2060927

Abstract: Longitudinal work suggests that sexual orientation can change over time in men and women. These studies, however, may be susceptible to the bias of self-report. The current study therefore examined self-reported sexual orientation in addition to an objective correlate: genital arousal to erotic videos showing males or females. For 52 men (19 heterosexual, 19 bisexual, 14 homosexual) and 67 women (31 heterosexual, 18 bisexual, 18 homosexual), these measures were taken twice, with approximately 1 year between sessions. For self-reported sexual orientation, women reported lower relative stability (weaker correlation) than men over time, even though women did not change more overall (no stronger mean difference) than men between sessions. Bisexual individuals reported lower relative stability and more mean change than heterosexual and homosexual individuals. For genital arousal, across all groups, response patterns were correlated over time to a similar extent and showed little difference between sessions. Moreover, change in self-reported sexual orientation did not correspond with the change in genital arousal, regardless of sex. Perhaps self-reports overestimate changes in sexual orientation, since these changes were not reflected in physiological sexual response.

Discussion

The present study examined: (a) the correlation of self-reported sexual orientation and arousal over time, (b) the mean change in orientation and arousal over time, and (c) the link between change in self-reported sexual orientation and change in sexual arousal. Before addressing any effects of time, it is worth examining the results by session. In general, patterns of sexual arousal in the present study were in agreement with those previously reported (Raines et al., 2021; Rosenthal et al., 2011). That is, heterosexual and homosexual men showed a strong preference for their preferred sex, while bisexual men, as a group, showed arousal to both sexes. Across sexual orientations, women showed arousal both to the same sex and other sex; however, homosexual women showed a slight tendency in arousal toward the same sex. One unexpected result was found in Session 1, where bisexual women showed somewhat less bisexual arousal than heterosexual women, if not homosexual women. It is unclear why this pattern occurred, and it was no longer the case in Session 2 (Figure 3).

With respect to relative stability (correlation) of self-reported sexual orientation over time, our results were similar to those found in a previous longitudinal study (Savin-Williams et al., 2012): (1) sexual orientation was relatively stable, overall, as suggested by the correspondence between sessions, (2) women, in general, showed lower relative stability than men, and (3) bisexuals, irrespective of sex, reported lower relative stability than other sexual orientations. For sexual arousal we also found overall relative stability, but it was weaker than for sexual orientation. Moreover, a sex difference in relative stability was only apparent in one of the two measures of arousal, and no significant differences in relative stability were found between bisexuals and monosexuals.

With respect to change (mean difference), for self-reported sexual orientation, our results were somewhat in agreement with previous work, but not entirely so (Mock & Eibach, 2012; Ott et al., 2011; Savin-Williams et al., 2012): (1) even though we did not find directional change over time, on average, there was non-directional change in participants’ sexual orientations, (2) even though women did not exhibit more non-directional change than men, the difference was in the predicted direction, and (3) bisexual individuals changed non-directionally more than other sexual orientations. Regarding mean change in sexual arousal, our results only partially mirrored findings for sexual orientation: (1) non-directional mean change in sexual arousal occurred, on average, but (2) women did not change more than men, and (3) bisexual individuals did not change more than monosexuals. In sum, 5 out of 6 of our predictions related to relative stability and to change were confirmed for self-reported sexual orientation, whereas only 2 out of 6 were fully confirmed across measures of genital arousal.

Taken together, the current data were able to largely replicate previous findings with respect to self-reported sexual orientation, but this was not reflected in sexual arousal. 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). 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. Limited support for this assumption comes from one of our null findings, which indicated that change in self-reported sexual orientation was unrelated to change in sexual arousal.

Other limitations of this work need to be considered. It may be that with our sample, the proportion of individuals who exhibited a change in sexual arousal (or orientation) is simply too small to detect any reliable patterns. For instance, we can see in Figures 3a and 3b that bisexual men responded more to their less-arousing sex at the second visit, even though this difference between sessions was not statistically significant. Our lab was forced to close during the COVID-19 pandemic, which meant we were unable to bring back as many participants as originally planned. Despite this limitation, we believe the current findings are informative and may be used as a basis for future longitudinal studies of sexual arousal, which could employ larger participant cohorts.

In addition, due to the intrusive nature of the procedure, which is unavoidable for research on genital arousal, our study may have suffered from self-selection bias, and we simply do not know how patterns would look in those who do not participate. Furthermore, our study does not inform how patterns may change over longer periods, over and above 1 year, and future research could investigate this.

Another worthwhile avenue for future research may be to include pupillary responses to sexually explicit stimuli as an alternative measure of sexual arousal (Attard-Johnson et al., 2021). Even though previous work suggests that genital arousal and pupil dilation tend to show comparable findings (Rieger et al., 2015), the latter produces more noise and smaller effects, on average, and therefore require more participants. Still, including both genital arousal and pupil dilation would be ideal in future longitudinal studies of sexual arousal.

Research could also examine relative stability and change in both self-reported sexual orientation and sexual arousal during specific developmental periods (e.g., before, during, and after puberty), if this were ethically justifiable. Further, one may examine the precise reasons why some individuals exhibit change in their self-reported sexual orientation or sexual arousal. For instance, fear of rejection, discrimination, and cultural norms are a few of the factors that might influence change in self-reported sexual orientation, while exposure to new sexual experiences might contribute to changes in sexual arousal.

Conclusion

In this study, we followed up men and women of varying sexual orientations over time, examining their self-reported sexual orientation and objectively assessing their genital arousal to sexually explicit stimuli. We found that, on average, change in self-reported sexual orientation was more likely to be reported than change in genital arousal in both men and women, and that among all sexual orientations, bisexual individuals were the most likely to report any change. Furthermore, we found that change in self-reported sexual orientation was not reflected in genital arousal, providing tentative support for the notion that self-reports may overestimate change in sexual orientation.