Sexual Arousal Patterns of Women: A Test of Alternative Hypotheses

与男性不同，女性的性行为没有得到充分的研究，也没有被科学和社会认真对待（奇弗斯，2016）。直到最近，人们才认识到女性的性取向是截然不同的（Bailey, 2009）：大多数女性，包括异性恋女性，对两种性别都有性唤起，而大多数男性只对一种偏好的性别有性唤起。这已经通过生殖器血管充血和瞳孔扩张来证明，无论是男性还是女性的性视频（Rieger et al., 2015）。关于女性独特的性唤起模式的一个突出的建议是，强迫交配发生在人类进化的整个过程中，女性保护生殖器免受伤害的压力是如此之大，以至于她们已经进化到以性唤起和润滑来回应任何性刺激，即使刺激在主观上是不唤起的（Suschinsky & lalumi<e:1>, 2011）。这一进化假说在一项评估润滑的研究中受到了挑战——这种方法很少被使用，但可能彻底改变我们对女性性唤起的理解。在该研究中，女性只对她们主观上喜欢的性视频感兴趣，而对其他类型的性视频没有兴趣，这质疑了该假设的有效性（Sawatsky, Dawson, & lalumi<e:1>, 2018）。此外，进化假说忽略了女性双性恋性兴奋模式的其他潜在原因。性唤起的性别差异可以归因于移情的性别差异。平均而言，与男性相比，女性具有更强的情感同理心（Stuijfzand et al., 2016），她们可能更有可能分享性视频中女性的情绪状态，并与她们一起体验性唤起。此外，女性在争取配偶时比男性更依赖于她们的外表吸引力，因此更容易被外表有吸引力的对手所困扰（Buunk & Fisher, 2009）。因此，女性可能会通过观看性爱视频中有吸引力的对手而从压力中被唤醒，而这种压力恰好触发了生理上的性唤起。在研究1中，我将通过测量270名不同性取向的男性和女性的生殖器血管充血和瞳孔扩张（用阴茎尺、阴道探头和眼动仪）来检验进化假说。我也会评估他们的主观觉醒，重要的是，每个视频的女性润滑（通过石蕊试纸）。性视频将包括描述演员的叙述，要么是一个有爱心的爱人，要么是一个寻求非自愿性行为的人（不会出现这样的行为），以测试女性是否对所有的性视频做出性反应，包括润滑，即使这些视频在主观上令人不快。研究2将使用与研究1相同的参与者。参与者自我报告的共情和性竞争（一般情况下，特别是对视频中的演员）将与性唤起的测量一起被评估，以检查女性的双性恋性唤起模式是否由于共情和性内竞争的性别差异。即使进化论假说不被支持，这种性别差异也可以被发现，因此提供了强有力的替代解释。研究3还将测试共情、竞争和性唤起方面的性别差异，但在实验室之外，通过在线实验，包括操纵参与者的共情和竞争，以检验因果关系和研究结果的普遍性。先进的定量方法将用于收集大数据集，混合因子回归，多重输入，以及对引导样本的中介分析。这项拟议中的研究将对女性性唤起的研究产生影响，因为它审视了一个突出但几乎没有经过检验的进化假设，并可能为其他解释提供证据。因此，这项研究可以增加我们对女性性行为的理解。

Unlike men's, women's sexuality is understudied and not taken as seriously by science and society (Chivers, 2016). It was only recently acknowledged that women's sexuality is profoundly different (Bailey, 2009): Most women, including heterosexual women, are sexually aroused to both genders, whereas most men are aroused to one preferred gender. This has been demonstrated with genital vasocongestion and pupil dilation to sexual videos showing males or females (Rieger et al., 2015).A prominent proposal for women's unique sexual arousal patterns is that forced copulation happened throughout human evolution, and the pressure for women to protect against genital injury was so strong that they have evolved to respond to any sexual stimulus with arousal and lubrication, even if the stimulus is subjectively un-arousing (Suschinsky & Lalumière, 2011). This evolutionary hypothesis has been challenged in one study assessing lubrication - a methodology that is rarely used but could revolutionise our understanding of women's sexual arousal. In that study, women only lubricated to their subjectively preferred sexual videos but to no other kind of sexual videos, which questions the validity of the hypothesis (Sawatsky, Dawson, & Lalumière, 2018).Furthermore, the evolutionary hypothesis ignores other potential reasons for women's bisexual arousal patterns. Sex differences in sexual arousal could be attributed to sex differences in empathy. As women have a greater affective empathy, on average, compared to men (Stuijfzand et al., 2016), they may be more likely to share the emotional state of females shown in sexual videos and experience the sexual arousal with them. Moreover, women, more than men, depend on their physical appeal when competing for mates, and are therefore more distressed by physically attractive rivals (Buunk & Fisher, 2009). Thus, women may be aroused from stress by viewing attractive rivals in sexual videos, and this stress coincidentally triggers physiological sexual arousal. In Study 1, I will examine the evolutionary hypothesis in 270 men and women with different sexual orientations by measuring their genital vasocongestion and pupil dilation (with penile gauges, vaginal probes, and eye trackers) to sexual videos showing males or females. I will also assess their subjective arousal and, importantly, women's lubrication (via litmus strips) to each video. Sexual videos will include narratives that describe the actor either as a caring lover or a person seeking non-consensual sex (no such acts will be shown), to test whether women respond sexually, including lubrication, to all sexual videos, even if these are subjectively unpleasant. Study 2 will use the same participants as Study 1. Participants' selfreported empathy and intrasexual competition (both in general, plus specifically towards the actors in the videos) will be assessed alongside measures of sexual arousal, to examine whether women's bisexual arousal pattern is due to sex differences in empathy and intrasexual competition. Such sex differences could be found even if the evolutionary hypothesis is not supported, and therefore offer powerful alternative explanations. Study 3 will also test sex differences in empathy, competition, and sexual arousal, but outside the lab via an online experiment that includes manipulations of participants' empathy and competition in order to examine causality and the generalisability of findings.Advanced Quantitative Methods will be used in the collection of large data sets, mix-factorial regressions, multiple imputations, and mediation analyses on boot-strapped samples. The proposed research will have an impact on the study of female sexual arousal by scrutinising a prominent but hardly tested evolutionary hypothesis, and by potentially providing evidence for alternative explanations. Thus, this research can increase our understanding of female sexuality.