The evolution and biopsychology of non-conceptive sexuality

有人说繁殖是推动进化的引擎。然而，非受孕性行为在人类和动物中普遍存在。乍一看，这种行为的存在似乎推翻了基本的进化理论，比如预测行为进化是为了促进繁殖的性选择理论。那么，为什么生物体会进行非受孕性行为呢？这个问题代表了心理学中最突出的悖论之一。我的研究计划的长期目标是了解为什么一些物种经常进行非受孕性行为，以及这种行为对整个交配系统的进化后果。为了实现这一目标，我对两种经常表达同性恋行为的灵长类物种进行了跨物种和跨文化研究。在过去的27年里，我一直在研究日本猕猴种群，它们的两性除了有性行为外，还经常进行同性恋和非怀孕异性恋行为。我还在萨摩亚（自2003年以来）和墨西哥瓦哈卡州的伊斯特莫地区（自2015年以来）进行了人类研究，在这两种文化中，同性吸引的跨性别男性被认定为非二元性别：分别为fa'afafine和muxes gunaa。萨摩亚的fa'afafine和Istmo Zapotec的muxe guna只与顺性男性进行性活动，而这些男性通常也与顺性女性进行性活动。重要的是，我的工作证明了其他研究人员直到最近才正式承认的生物学相关性；也就是说，生殖性和非受孕性是同步发展和进化的，每一方都可以影响另一方。通过阐明生殖性行为和非受孕性行为之间的动态相互作用，我的研究为思考人类和其他动物的性行为的发展和进化提供了变革的方式。关于性和性别多样性的讨论常常发生在信息真空中，这种真空是由个人政治和道德驱动的，但与任何实际证据脱节。我提出的NSERC研究计划提供了与学术界和公众目前正在争论的许多问题相关的心理生物学和进化数据。在此过程中，我的研究有助于纠正有偏见的、错误的或不正确的观点，并提供了一个基于证据的、与生物学相关的对性和性别多样性的理解的基础。通过科学场所以及国内和国际媒体积极传播我的研究成果，我促进了关于这些主题的更明智和客观的对话。这反过来又奠定了一个基础，在此基础上，可以在各级进行与性别和性别多样性有关的循证决策。

It has been said that reproduction is the engine that drives evolution. Nevertheless, non-conceptive sexual activity is widespread among humans and animals. At first glance, the existence of such behaviour seems to invalidate basic evolutionary theories, like sexual selection, which predict that behaviour evolves to facilitate reproduction. Why, then, do organisms engage in non-conceptive sex? This question represents one of the most outstanding paradoxes in psychology. The long-term goal of my research program is to understand why some species routinely engage in non-conceptive sexual behaviour and what the evolutionary consequences of such behaviour are for mating systems as a whole. To achieve this goal, I conduct cross-species and cross-cultural research on two primate species in which homosexual behaviour is frequently expressed. For the past 27 years, I have studied Japanese macaque populations in which both sexes regularly engage in homosexual and non-conceptive heterosexual behaviour, in addition to reproductive sex. I have also conducted human research in Samoa (since 2003) and in the Istmo region of Oaxaca, Mexico (since 2015), both cultures in which same-sex attracted transgender males are identified as non-binary genders: fa'afafine and muxes gunaa, respectively. Samoan fa'afafine and Istmo Zapotec muxe gunaa only engage in sexual activity with cisgender men, who, in turn, commonly engage in sexual activity with cisgender women as well. Significantly, my work demonstrates what other researchers have only recently come to formally acknowledge as biologically relevant; namely, that reproductive and non-conceptive sex develop and evolve in concert, and each can influence the other. By illuminating the dynamic interplay between reproductive and non-conceptive sex, my research furnishes transformative ways of thinking about the development and evolution of sexuality in humans and other animals. All too often discussions about sexual and gender diversity occur in an information vacuum that is driven by personal politics and morality, but divorced from any actual evidence. My proposed NSERC research program provides the psychobiological and evolutionary data relevant to many of the issues that are being currently debated among academics and the public. In doing so, my research helps to correct biased, erroneous, or incorrect views and provides a basis upon which an evidence-based, biologically relevant understanding of sexual and gender diversity can be situated. By actively disseminating my research results through scientific venues, as well as through the national and international media, I facilitate more intelligent and objective conversations about these topics. This, in turn, furnishes a foundation upon which evidence-based decision making related to sex and gender diversity can occur at all levels.