ISPA, Unidade de Investigação em Eco-Etologia (Eco-Ethology Research Unit) ISPA, Lisbon, Portugal.
J Sex Med. 2012 Dec;9(12):3079-88. doi: 10.1111/j.1743-6109.2012.02917.x. Epub 2012 Sep 24.
Research indicates that (i) women's orgasm during penile-vaginal intercourse (PVI) is influenced by fitness-related male partner characteristics, (ii) penis size is important for many women, and (iii) preference for a longer penis is associated with greater vaginal orgasm consistency (triggered by PVI without concurrent clitoral masturbation).
To test the hypothesis that vaginal orgasm frequency is associated with women's reporting that a longer than average penis is more likely to provoke their PVI orgasm.
Three hundred twenty-three women reported in an online survey their past month frequency of various sexual behaviors (including PVI, vaginal orgasm, and clitoral orgasm), the effects of a longer than average penis on likelihood of orgasm from PVI, and the importance they attributed to PVI and to noncoital sex.
Univariate analyses of covariance with dependent variables being frequencies of various sexual behaviors and types of orgasm and with independent variable being women reporting vs. not reporting that a longer than average penis is important for their orgasm from PVI.
Likelihood of orgasm with a longer penis was related to greater vaginal orgasm frequency but unrelated to frequencies of other sexual behaviors, including clitoral orgasm. In binary logistic regression, likelihood of orgasm with a longer penis was related to greater importance attributed to PVI and lesser importance attributed to noncoital sex.
Women who prefer deeper penile-vaginal stimulation are more likely to have vaginal orgasm, consistent with vaginal orgasm evolving as part of a female mate choice system favoring somewhat larger than average penises. Future research could extend the findings by overcoming limitations related to more precise measurement of penis length (to the pubis and pressed close to the pubic bone) and girth, and large representative samples. Future experimental research might assess to what extent different penis sizes influence women's satisfaction and likelihood of vaginal orgasm.
研究表明：（i）女性在阴茎阴道交（PVI）过程中的性高潮受到与健康相关的男性伴侣特征的影响；（ii）阴茎大小对许多女性很重要；（iii）偏爱更长的阴茎与更大的阴道性高潮一致性（通过不伴有同时阴蒂自慰的 PVI 触发）相关。
检验假设，即阴道性高潮的频率与女性报告称，长于平均长度的阴茎更有可能引发其 PVI 性高潮。
323 名女性在一项在线调查中报告了她们过去一个月中各种性行为（包括 PVI、阴道性高潮和阴蒂性高潮）的频率、长于平均长度的阴茎对 PVI 性高潮可能性的影响，以及她们对 PVI 和非性交性爱的重视程度。
以各种性行为和性高潮类型的频率为因变量，以女性报告长于平均长度的阴茎对其 PVI 性高潮的重要性为自变量，进行单变量协方差分析。
更长阴茎的性高潮可能性与更大的阴道性高潮频率相关，而与其他性行为频率（包括阴蒂性高潮）无关。在二项逻辑回归中，更长阴茎的性高潮可能性与对 PVI 的重视程度增加和对非性交性爱的重视程度降低有关。
更喜欢深度阴茎阴道刺激的女性更有可能获得阴道性高潮，这与阴道性高潮作为女性择偶系统的一部分进化，倾向于稍微大于平均长度的阴茎相一致。未来的研究可以通过克服与更精确测量阴茎长度（耻骨上方和紧贴耻骨）和周长以及大代表性样本相关的局限性来扩展这些发现。未来的实验研究可能会评估不同的阴茎大小在多大程度上影响女性的满意度和阴道性高潮的可能性。
