Davidson Charles, Buckley Declan, Benenson Joyce F
Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
Biol Lett. 2024 Dec;20(12):20240487. doi: 10.1098/rsbl.2024.0487. Epub 2024 Dec 18.
Across diverse species with sexual reproduction, typically the more male-biased the adult sex ratio (ASR), the greater the investments by the more populous males in the rarer females who hold greater bargaining power in a mating context. Relatively few studies have examined this effect in humans however, and almost none involve observations of actual male investment in a potential mating context. Here, we present one of the first studies to observe investments of men in a potential mating context under differing ASRs. Across 163 mixed-sex groups from three taverns on 7 days of observation, we measured both a group's ASR and each group's leading man's latency to position himself at the tavern's bar to order and pay for beverages. The higher the proportion of men in a group (ASR) and the fewer the absolute number of women in a group, the faster the leading man in the group travelled to reach the bar to order and pay for beverages. Results are consistent with the hypothesis that similar to males in many species, men tactically regulate their investments to adapt to the fluctuation in the ASR in order to maximize their probabilities of attracting a mate.
在进行有性繁殖的各种物种中，通常成年性别比（ASR）越偏向雄性，数量较多的雄性对较稀少的雌性的投资就越大，因为这些雌性在交配情境中拥有更大的议价能力。然而，相对较少的研究在人类中检验过这种效应，而且几乎没有研究涉及在实际的潜在交配情境中观察男性的投资行为。在此，我们呈现了首批研究之一，即在不同成年性别比情况下观察男性在潜在交配情境中的投资行为。在7天的观察期内，我们对来自三家酒馆的163个混合性别人群进行了研究，测量了每个群体的成年性别比以及每个群体中领头男性在酒馆吧台前点单和付款的反应时间。一个群体中男性的比例（成年性别比）越高且女性的绝对数量越少，该群体中的领头男性走到吧台点单和付款的速度就越快。研究结果与以下假设一致：与许多物种中的雄性相似，男性会策略性地调整自己的投资行为，以适应成年性别比的波动，从而最大程度地提高吸引配偶的概率。
