Volunteer bias in erotica research: Effects of intrusiveness of measure and sexual background

Abstract

Volunteer characteristics and volunteer rates across several laboratory experiments of sexual arousal were compared. Conditions were created to assess which component of the experimental setting was responsible for low volunteer rates in experiments using genital measurement. Subjects were 324 male and 424 female undergraduate students who had volunteered for an experiment on sexuality and personality. After completing several measures of sexual experience and attitude, subjects received a written description of one of the following conditions and were asked if they wished to volunteer: sexual film, sexual film and subjective rating of arousal, sexual film and assessment through forehead temperature, sexual film and assessment with a device that was placed over the clothes and measured genital heat flow, sexual film and assessment with the heat flow device while partially undressed, or sexual film and assessment with the vaginal photoplethysmograph or penile strain gauge while partially undressed. Men were significantly more likely to volunteer than women, and volunteer rates for both men and women decreased significantly when and only when subjects were required to undress. Multivariate analyses of variance revealed that both male and female volunteers were more sexually experienced, reported more exposure to erotic materials, and worried less about their sexual performance than nonvolunteers. No differences in volunteer characteristics occurred across the increasingly intrusive conditions for women while a few differences occurred for men. The present findings suggest that researchers should be cautious about discussing the generality of findings of studies involving exposure to a sexually explicit film alone as well as of experiments that involve self-report or physiological measures of sexual arousal.

Feederism: An Exaggeration of a Normative Mate Selection Preference?

“…There is a selection bias in sexual psychophysiology research, such that individuals who volunteer to participate in sexual psychophysiology experiments are typically more sexually experienced, less concerned about their performance, and have been exposed to more erotica than individuals who do not volunteer to participate (Wolchik, Braver, & Jensen, 1985). That being said, Chivers, Rieger, Latty, and Bailey (2004) suggested that although volunteers differ from non-volunteers in terms of sexual experience, it does not mean that people who volunteer have significantly different patterns of arousal.…”

Effects of Experimentally Adopted Sexual Schemas on Vaginal Response and Subjective Sexual Arousal: A Comparison Between Women with Sexual Arousal Disorder and Sexually Healthy Women

“…First, participants consisted of volunteers who chose to participate in a study on sexuality. Volunteer bias has been demonstrated in studies involving sexuality (Wolchik, Braver, & Jensen, 1985) and, as such, the generalizability of these results is unknown. Second, because of the relatively small sample in the two groups, the proposed sub-types of FSAD could not be examined.…”

Effects of Gender and Relationship Context in Audio Narratives on Genital and Subjective Sexual Response in Heterosexual Women and Men

“…As with all sexual psychophysiology research, the generalizability of laboratory findings is a concern (Morokoff, 1986;Wolchik, Braver, & Jensen, 1985). The consistency with which women's nonspecific genital response, and low agreement with genital response, has been obtained across stimulus modality and measurement methods, however, mitigates these concerns and suggests nonspecificity of heterosexual women's genital arousal is not epiphenomenal or artifactual.…”