Data from: Evolutionary pressures on primate intertemporal choice

From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species' environment. Here, I use phylogenetic regression to test whether allometric factors (relating to body size), relative brain size, and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes body mass, absolute brain size, lifespan, and home range size predicted waiting times, but relative brain size and social group size did not. These findings support the notion that selective pressures have sculpted intertemporal choices to solve adaptive problems faced by animals. Collecting these types of data across a large number of species can provide key insights into the evolution of decision making and cognition.

从觅食活动到配偶选择，动物均需做出跨期选择（intertemporal choice），这类抉择涉及不同时间节点下可获取的适应度收益。不同物种对延迟奖励的耐受意愿存在显著差异，为何跨物种间会存在这种差异？跨期选择的适应性研究取向认为，物种的时间偏好应当反映其所处环境中的时序性适应难题。本研究采用系统发育回归（phylogenetic regression）方法，检验异速因子（allometric factors，与体型相关）、相对脑容量以及社会群体规模能否预测13种灵长类动物在实验室跨期选择任务中的等待时长。在控制系统发育效应后，包含体重、绝对脑容量、寿命以及家域范围大小的综合异速因子能够显著预测等待时长，但相对脑容量与社会群体规模则无此预测效力。上述研究结果支持这一观点：选择压力塑造了动物的跨期选择行为，以应对其面临的适应性生存问题。针对大量物种收集此类研究数据，能够为决策行为与认知能力的进化研究提供关键洞见。