Table_1_Sex Differences in Attitudes Toward Casual Sex: Using STI Contraction Likelihoods to Assess Evolved Mating Strategies.docx

Previous work shows that males are more likely to pursue casual sex if given the opportunity, compared to females, on average. One component of this strategy is risk-taking, and males have been shown to take more risks than females in a variety of contexts. Here, we investigate the extent to which sex differences exist considering casual sexual encounters involving sexually transmitted infections (STIs) using a hypothetical sexual scenario which attempts to circumvent several factors that may contribute to a female’s hesitancy to engage in casual sex encounters. Two hundred and forty-six college students rated their willingness to engage in a satisfying casual sexual encounter with someone judged to be personable as a function of sex, varying STI contraction likelihoods, several STI types, and two levels of hypothetical partner attractiveness. We also assess how individual levels of sociosexuality (as measured by the SOI-R) impact findings. Our findings show that males report higher likelihoods of sexual engagement compared to females in general. This trend continued for lower likelihoods of STI contraction in all four STI types (Cold, Chlamydia, Herpes, HIV), with larger effects shown in the high attractiveness partner condition. For higher STI contraction likelihoods and more severe STI types, along with lower partner attractiveness levels, sex differences shrank. Factoring in participant SOI-R scores attenuated the effects somewhat, although it failed to alter findings substantially with predicted sex differences continuing to exist. These results offer further insight into evolved sex differences in human mating systems and provide an additional framework to test sexual risk-taking among males and females.

既往研究表明，平均而言，男性在有机会时比女性更倾向于发生随意性行为。该策略的其中一个组成部分是冒险行为，已有研究显示，在多种情境下男性的冒险倾向均高于女性。本研究通过构建假想性情境，尝试规避可能导致女性对随意性行为持犹豫态度的多项因素，以此探究在涉及性传播感染（sexually transmitted infections, STIs）的随意性接触场景中是否存在性别差异。本研究共招募246名大学生，让他们基于自身性别、不同的性传播感染概率、四类性传播感染类型（普通感冒（Cold）、衣原体感染（Chlamydia）、疱疹（Herpes）、人类免疫缺陷病毒（HIV））以及两种假想伴侣吸引力水平，对与一位被认为具有亲和力的对象发生满意的随意性行为的意愿进行评分。我们还评估了性态度（sociosexuality）个体水平（通过性态度量表修订版（SOI-R）进行测量）对研究结果的影响。研究结果显示，总体而言男性报告的性行为参与意愿高于女性。在感染概率较低时，这一趋势在所有四类性传播感染类型中均成立，且在高吸引力伴侣情境中的效应量更大。而当感染概率较高、感染类型更为严重，以及伴侣吸引力较低时，性别差异会缩小。将参与者的SOI-R得分纳入考量后，上述效应会有所减弱，但并未从根本上改变研究结果，预测的性别差异依然存在。本研究结果进一步揭示了人类交配系统中演化而来的性别差异，并为检验男女两性的性冒险行为提供了额外的研究框架。