The Division of Emotional Labour: How a Dual Affective System Differentially Tracks Time and Rewards

Do different moods serve distinct adaptive functions by tracking different aspects of our environment? We investigate whether three momentary moods—happiness, frustration, and boredom—differentially respond to the passage of time and reward in two experimental conditions: a reward-deprived rest period and a gambling task. We show (among UK/US young adults recruited online; pilot: n = 75; validation: n = 265) that during rest, all moods demonstrate temporal drift: happiness decreases while boredom and frustration increase over time. During the gambling task, both happiness and frustration track reward outcomes significantly more than boredom, while boredom continues to monitor time passage. Additionally, more time is spent in negative moods for those scoring higher in clinical traits like irritability. This dual-system model of affective monitoring is a possible mechanism for how decisions incorporate time—through the representation of time in subjective affect—suggesting specialised adaptive roles for different moods in environmental monitoring.