Although both human and non-human animals, in everyday life, deal with risky decisions in a social environment, few studies investigated how social dimension influences risk preferences (i.e., if consequences on others feeds back over own choice). Here, we assessed whether the presence of a conspecific, acting as a potential competitor for the same food resource, influenced risky decision-making in male rats. Subjects received a series of choices between a safe option (always yielding a small yet optimal reward, solely to itself) and a risky option (yielding a larger but suboptimal reward, one third of times to itself and two third of times delivered to the other half cage); rats were tested twice, both alone and paired with a conspecific, recipient of own-lost food and hence acting as potential competitor. Results showed that focal subjects were more risk-prone when paired with a conspecific than when tested alone. However, rats exhibited also a higher motivational conflict with a competing bystander present than alone: data suggest that the primary drive was to increase "own" food rather than either a competitive or prosocial tendency. Overall, for rats tested in a risky-choice task, a competitive social context increased the salience and attractiveness of larger food outcomes, as observed in humans and great apes. This led to the economically irrational response of selecting the “binge-but-risky” option, notwithstanding uncertainty about the actual recipient of such food.

尽管人类和非人类动物在日常生活中都会处理社会环境中的风险决策，但很少有研究调查社会维度如何影响风险偏好（即，如果对他人的后果反馈到自己的选择之上）。在这里，我们评估了作为同一食物资源的潜在竞争对手的同种动物的存在是否会影响雄性大鼠的风险决策。受试者在安全选项（总是只为自己产生小而最佳的奖励）和风险选项（产生较大但次优的奖励，三分之一给自己，三分之二给对方）之间接受了一系列选择半笼）；老鼠被测试了两次，单独和配对，接受自己丢失的食物，因此成为潜在的竞争对手。结果表明，与单独测试相比，与同种配对时，焦点受试者更容易冒险。然而，与单独在场的竞争旁观者相比，老鼠也表现出更高的动机冲突：数据表明，主要驱动力是增加“自己的”食物，而不是竞争或亲社会倾向。总体而言，对于在风险选择任务中进行测试的大鼠，竞争激烈的社会环境增加了更大食物结果的显着性和吸引力，正如在人类和类人猿中观察到的那样。这导致选择“暴饮暴食但有风险”选项的经济上不合理的反应，尽管这种食物的实际接受者不确定。与单独在场的竞争旁观者相比，老鼠也表现出更高的动机冲突：数据表明，主要驱动力是增加“自己的”食物，而不是竞争或亲社会倾向。总体而言，对于在风险选择任务中进行测试的大鼠，竞争激烈的社会环境增加了更大食物结果的显着性和吸引力，正如在人类和类人猿中观察到的那样。这导致选择“暴饮暴食但有风险”选项的经济上不合理的反应，尽管这种食物的实际接受者不确定。与单独在场的竞争旁观者相比，老鼠也表现出更高的动机冲突：数据表明，主要驱动力是增加“自己的”食物，而不是竞争或亲社会倾向。总体而言，对于在风险选择任务中进行测试的大鼠，竞争激烈的社会环境增加了更大食物结果的显着性和吸引力，正如在人类和类人猿中观察到的那样。这导致选择“暴饮暴食但有风险”选项的经济上不合理的反应，尽管这种食物的实际接受者不确定。正如在人类和类人猿身上观察到的那样。这导致选择“暴饮暴食但有风险”选项的经济上不合理的反应，尽管这种食物的实际接受者不确定。正如在人类和类人猿身上观察到的那样。这导致选择“暴饮暴食但有风险”选项的经济上不合理的反应，尽管这种食物的实际接受者不确定。