Research in nonhuman animals (including insects, birds, and primates) suggests a trade-off in males between investment in competitive traits and investment in ejaculate quality. Previous research reported a negative association between perceived strength and ejaculate quality, suggesting that this trade-off also applies to human males. We conducted novel analyses of data secured as part of a larger project to assess the relationship between competitive traits (shoulder-to-hip ratio, handgrip strength, and height) and ejaculate quality (indexed by sperm morphology, sperm motility, and sperm concentration) in a sample of 45 men (ages ranging 18–33 years; M = 23.30, SD = 3.60). By self-report, participants had not had a vasectomy and had never sought treatment for infertility. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationships between competitive traits and ejaculate quality; our findings therefore do not accord with previous research on humans. We highlight the need for additional research to clarify whether there is a trade-off between investment in competitive traits and investment in ejaculate quality in humans.

对非人类动物（包括昆虫、鸟类和灵长类动物）的研究表明，雄性在竞争性状投资和射精质量投资之间需要权衡。先前的研究报告称，感知力量与射精质量之间存在负相关关系，表明这种权衡也适用于人类男性。我们对作为大型项目一部分获得的数据进行了新颖的分析，以评估竞争特征（肩臀比、握力和身高）与射精质量（以精子形态、精子活力和精子浓度为索引）之间的关系45 名男性样本（年龄范围 18-33 岁；M = 23.30，SD = 3.60）。根据自我报告，参与者没有进行输精管结扎术，也从未寻求不孕症治疗。我们控制了几个已知影响射精质量的协变量（例如，射精前的禁欲持续时间），发现竞争性状和射精质量之间没有统计学上的显着关系。因此，我们的研究结果与之前对人类的研究不符。我们强调需要进行更多研究，以澄清对竞争性状的投资和对人类射精质量的投资之间是否存在权衡。