Research in human sexuality is essential due to its impact on people's sexual health and well-being, although it is sometimes perceived as innovative, different, or unconventional. Consequently, participating in sexuality studies might mean that only specific individuals, with certain characteristics, show interest in participating, which would result in significant methodological bias due to a lack of sample representativeness. This bias could be more pronounced in studies involving psychophysiological measures of genital response (e.g., penile erection or vaginal pulse amplitude recordings), as they are perceived as intrusive methods in people’s intimacy. Despite this evidence, few studies have addressed this potential bias.
Researchers at the Human Sexuality Laboratory (LabSex UGR), Ana Isabel Arcos-Romero, Ana Álvarez-Muelas, Óscar Cervilla, and Juan Carlos Sierra, have published a study in Sexuality & Culture comparing different psychosexual characteristics (erotophilia, propensity for sexual excitation/inhibition, and subjective orgasmic experience) between individuals who volunteer to participate in sexuality studies that include genital response recordings and the general population. Specifically, the study compared 525 young adults (205 men and 320 women) interested in participating in studies where their erection or vaginal pulse amplitude would be recorded while watching a sexually explicit video, with young individuals of the same age and sex from the general population.
The results showed that women volunteers reported higher erotophilia (i.e., a more positive attitude toward sexuality), greater propensity for sexual excitation, lower propensity for sexual inhibition, and lower intensity in the affective, sensory, and intimate dimensions of subjective orgasmic experience compared to women in the general population. Men volunteers differed from the general population only in their subjective orgasmic experience, experiencing less intense orgasms. The comparison between men and women interested in participating in laboratory studies indicated that women reported higher scores in erotophilia and sexual inhibition due to fear of performance failure and greater intensity in the sensory dimension of orgasm.
These results may reflect, on the one hand, a shift toward more positive sexual scripts among women and, on the other, that volunteers for sexuality laboratory studies may exhibit greater awareness of their sexual experience and a desire to learn more about their sexual response, given the less intense perception of their orgasmic experience.
In conclusion, individuals volunteering for studies involving psychophysiological recordings of genital response may present different psychosexual characteristics from the general population, which could impact the generalizability of the findings to the broader population.