Seasonal cycles in morality and prejudice

Many animal species exhibit seasonal changes in their physiology and behavior. Human psychology is seasonal, too. Despite ample evidence that our emotions, thoughts, and behaviors are shaped by seasonal cycles, little empirical evidence speaks to the effects seasons may have on social cognition. Here, I present evidence that people’s moral values and prejudices change with the seasons. Chapter 1 outlines the many ways seasons can influence human psychology and provides an illustrative summary of empirical evidence showing that seasons impact a wide range of affective, cognitive, and behavioral phenomena. Chapter 2 investigates whether Americans’ moral values change with the seasons using a large cross-sectional dataset. Chapter 3 conceptually replicates the findings of Chapter 2 using a longitudinal design. Chapter 4 extends this work by testing for seasonal effects on direct (explicit) and indirect (implicit) measures of prejudice against nine disadvantaged social groups. Chapter 5 discusses the importance of accounting for seasonal cycles when forecasting the effects of climate change on psychological phenomena. It then provides an analytic strategy for developing seasonally sensitive forecasts. Chapter 6 discusses the mechanisms underlying these seasonal effects, possibilities for future research, and the broader implications of this work for psychological science.