The effect of opportunity costs on mental fatigue in labor/leisure tradeoffs

Most people experience the feeling of mental fatigue on a daily basis. Previous research shows that mental fatigue impacts information processing and decision making. However, the proximal causes of mental fatigue are not yet well understood. In this research, we test the opportunity cost model of mental fatigue, which proposes that people become more fatigued when the next-best alternative to the current task is higher in value. In four preregistered experiments (total N = 430), participants repeatedly reported their current level of fatigue and chose to perform a paid labor task vs an unpaid leisure task. In Study 1, all participants were offered the same labor/leisure choice. In Studies 2 and 3, we manipulated the opportunity costs of a labor task by varying the value of an alternative leisure task. In Study 4, we manipulated the opportunity costs of a labor task by varying the value of that labor task. In all studies, we found that people were more likely to choose for leisure as they became more fatigued. In Studies 2–4, we did not find that the manipulated leisure value influenced the amount of fatigue participants experienced nor the likelihood to choose for leisure. However, in exploratory analyses, in all studies, we found (and replicated) that participants who reported to value the leisure task more got more fatigued during labor and less fatigued during leisure. Collectively, these results provide cautious support for the opportunity cost model, but they also show that cost-benefit analyses relating to labor and leisure tasks are fleeting.

绝大多数人每日均会经历心理疲劳之感。既往研究表明，心理疲劳对信息处理与决策制定产生显著影响。然而，心理疲劳的近端成因尚未得到充分认知。在本项研究中，我们检验了心理疲劳的机会成本模型，该模型提出，当当前任务的最佳替代方案价值更高时，个体会感到更加疲劳。在四项预先注册的实验（总样本量 N = 430）中，参与者反复报告自身当前的疲劳程度，并选择执行付费劳动任务或无偿休闲任务。在第一项研究中，所有参与者均面临相同的劳动/休闲选择。在第二项和第三项研究中，我们通过改变替代休闲任务的价值来操纵劳动任务的机会成本。在第四项研究中，我们通过改变劳动任务的价值来操纵劳动任务的机会成本。在所有研究中，我们发现随着疲劳程度的增加，人们更有可能选择休闲活动。在第二项至第四项研究中，我们没有发现操纵休闲价值会影响参与者所经历的疲劳程度或选择休闲活动的可能性。然而，在探索性分析中，我们发现（并验证）了所有研究中，那些报告更重视休闲任务的参与者，在劳动期间感到的疲劳更为严重，而在休闲期间感到的疲劳则相对较轻。综上所述，这些结果谨慎地支持了机会成本模型，同时也表明与劳动和休闲任务相关的成本效益分析是瞬息万变的。