Abstract
Our study examines how chronic sleep restriction and suboptimal times-of-day affect decisions in a classic set of social tasks. We experimentally manipulate and objectively measured sleep in 184 young-adult subjects, who were also randomly assigned an early morning or late evening experiment session during which decision tasks were administered. Sleep restriction and suboptimal time-of-day are both estimated to either directly or indirectly (via an impact on sleepiness) reduce altruism, trust, and trustworthiness. We conclude that commonly experienced adverse sleep states, most notably chronic sleep restriction, significantly reduce prosocial behaviors, and can therefore limit benefits from short-term social interactions.