Introduction
Sleep is essential to human life, but it has been largely overlooked in studying political phenomena. Sleep research presents an important frontier of discovery for political science. This nascent area is already producing illuminating findings. Inadequate sleep lowers turnout (Holbein et al., Reference Holbein, Schafer and Dickinson2019; Potoski & Urbatsch, Reference Potoski and Urbatsch2017; Schafer & Holbein, Reference Schafer and Holbein2020; Urbatsch, Reference Urbatsch2014, Reference Urbatsch2017), as does excessive sleep (Ksiazkiewicz & Erol, Reference Ksiazkiewicz and Erol2022). Contentious political events, like the Brexit vote and the Donald Trump’s election, cause people to sleep less (Anýž et al., Reference Anýž, Bakštein, Dudysová, Veldová, Kliková, Fárková, Kopřivová and Španiel2019). Conservatives are more likely to be larks (early to bed, early to rise) than night owls (Ksiazkiewicz, Reference Ksiazkiewicz2020), and they are also more likely than liberals to value morning more than night (Ksiazkiewicz, Reference Ksiazkiewicz2021). The links between sleep and politics that have been identified so far are consequential; many more are waiting to be discovered.
While sleep has largely been neglected by political scientists, human psychology is inextricably linked with sleep and so political cognition must be as well. Adequate sleep is linked to prosociality (Dickinson & McElroy, Reference Dickinson and McElroy2017), health (Fabbian et al., Reference Fabbian, Zucchi, De Giorgi, Tiseo, Boari, Salmi, Cappadona, Gianesini, Bassi, Signani, Raparelli, Basili and Manfredini2016), and educational attainment (Dewald et al., Reference Dewald, Meijer, Oort, Kerkhof and Bögels2010), all outcomes with important political implications. Chronotype has been linked to politically meaningful psychological traits, such as the Big Five (Lipnevich et al., Reference Lipnevich, Credè, Hahn, Spinath, Roberts and Preckel2017) and the Dark Triad (Jonason et al., Reference Jonason, Jones and Lyons2013), and with demographic characteristics, such as urban-rural residence (Carvalho et al., Reference Carvalho, Hidalgo and Levandovski2014), age, and sex (Fischer et al., Reference Fischer, Lombardi, Marucci-Wellman and Roenneberg2017). Inadequate sleep is linked to cognitive burdens (Killgore, Reference Killgore2010; Vaseghi et al., Reference Vaseghi, Arjmandi-Rad, Kholghi and Nasehi2021); cognitive load affects ideological cognition (Eidelman et al., Reference Eidelman, Crandall, Goodman and Blanchar2012), decision-making (Deck & Jahedi, Reference Deck and Jahedi2015), especially as complexity increases (Allred et al., Reference Allred, Duffy and Smith2016), candidate evaluation (Nawara & Bailey, Reference Nawara and Bailey2021), and the processing of news information (Van Cauwenberge et al., Reference Van Cauwenberge, Schaap and van Roy2014). Sleep deficits also disrupt emotion regulation (Palmer & Alfano, Reference Palmer and Alfano2017), which may make politics more stressful (Ford & Feinberg, Reference Ford and Feinberg2020). In short, findings in sleep science have clear relevance for questions at the core of political science.
These effects are particularly worrisome as inadequate sleep (less than seven hours; Hirshkowitz et al., Reference Hirshkowitz, Whiton, Albert, Alessi, Bruni, DonCarlos, Hazen, Herman, Adams Hillard, Katz, Kheirandish-Gozal, Neubauer, O’Donnell, Ohayon, Peever, Rawding, Sachdeva, Setters, Vitiello and Ware2015) is a problem for 35% of the American public (Centers for Disease Control and Prevention [CDC], 2017) and, likely, a sizeable percentage of political elites (cf. Barnes & Spreitzer, Reference Barnes and Spreitzer2015). Access to sleep is also an issue of social justice; insufficient sleep is a problem for 33% of White Americans, but 46% of Black Americans (CDC, 2017), and sleep quality is a crucial link between socioeconomic status and well-being (Mezick et al., Reference Mezick, Matthews, Hall, Strollo, Buysse, Kamarck, Owens and Reis2008; Moore et al., Reference Moore, Adler, Williams and Jackson2002). Taken together, insufficient sleep has significant aggregate economic costs (Hafner et al., Reference Hafner, Stepanek, Taylor, Troxel and van Stolk2017), but its effects on the functioning of democratic institutions are poorly understood.
An agenda for sleep and politics
Political scientists are uniquely positioned to uncover the links between sleep and the health of democracy. I suggest three pathways forward—on participatory democracy, on ideology, and on the way that context shapes sleep-politics links—but many other directions should also be explored.
Persuasion and mobilization are core topics in studying participatory democracy. Researchers should use experiments to examine how voters with different sleep patterns are affected by campaign messages throughout the day. Time of day is a critical variable in reasoning, with early risers processing arguments systematically in the morning and heuristically in the evening (with the reverse for night owls; Martin & Martin, Reference Martin and Martin2013). Given that a third of the American electorate experiences inadequate sleep, understanding the political consequences of cognitive impairments from insufficient sleep is vital for building a resilient political system.
In the United States, morning types are more politically conservative on average (Ksiazkiewicz, Reference Ksiazkiewicz2020; cf. Ksiazkiewicz & Erol, Reference Ksiazkiewicz and Erolforthcoming), but it remains an open question why morningness and conservatism are linked. The 9-to-5, “early bird gets the worm” organization of professional life may nudge morning types to accept the social status quo because it aligns with their predispositions, while simultaneously alienating evening types. Conversely, surveys that focus on chronotype as a social identity (Ksiazkiewicz, Reference Ksiazkiewicz2021) have opened the possibility of reciprocal effects. Ideology may instead affect how a person structures their daily time, including sleep habits. Longitudinal studies could help sort out the direction of causation. Twin studies could supplement this work by uncovering the common roots of sleep behaviors and political attitudes, such as shared genetic or environmental influences.
Finally, the relationships identified so far—sleep duration and turnout, sleep timing and ideology, political stress and sleep loss—differ across contexts. Comparative and subnational research could expand the breadth of our understanding by identifying contextual differences in the relationships between sleep and politics. This could include variation across social groups, across regions or environments within countries (e.g., urban-rural or by local polarization), and between countries where cultural or geographic factors may mitigate or exacerbate—or, indeed, create—links between sleep and politics.
Broader implications
Beyond these three pathways forward, there is potential for further scientific discovery. Consider how electoral institutions can have disparate impacts by sleep status (Urbatsch, Reference Urbatsch2017), the decision-making consequences of inadequate sleep among political elites (Wiegele, Reference Wiegele1973), or the effect of military conflict on sleep loss among soldiers (Neylan et al., Reference Neylan, Marmar, Metzler, Weiss, Zatzick, Delucchi, Wu and Schoenfeld1998; Pruiksma & Peterson, Reference Pruiksma, Peterson, Vermetten, Germain and Neylan2018) and civilians (Palmieri et al., Reference Palmieri, Chipman, Canetti, Johnson and Hobfoll2010). Some normative scholars argue for a right to sleep (Goldberg-Hiller, Reference Goldberg-Hiller2019). Existing sleep studies in political science rely primarily on self-reports of sleep duration and timing, which may be subject to biases and may miss other sleep behaviors like napping (Bessone et al., Reference Bessone, Rao, Schilbach, Schofield and Toma2021; Schokman et al., Reference Schokman, Bin, Simonelli, Pye, Morris, Sumathipala, Siribaddana, Hotopf, Rijsdijk, Jayaweera and Glozier2018). Nonetheless, existing studies could be supplemented by a wide variety of other measures of sleep (e.g., sleep diaries, sleep quality, insomnia identity), untapped data sources (e.g., public health data, collaboration with sleep labs, data from sleep trackers, wearables, or social media activity), and the potential for using experiments to disentangle causality (cf. Bessone et al., Reference Bessone, Rao, Schilbach, Schofield and Toma2021; Holbein et al., Reference Holbein, Schafer and Dickinson2019).
Ensuring adequate sleep should be a key policy goal. Sleep should be understood as a national resource that is vital to our physical and mental health, to the economy, and, ultimately, to our democracy. Political scientists could contribute to policy deliberations regarding school start times (Troxel & Wolfson, Reference Troxel and Wolfson2017), daylight saving time (Rishi et al., Reference Rishi, Ahmed, Barrantes, Berneking, Dombrowsky, Flynn-Evans, Santiago, Sullivan, Upender, Yuen, Abbasi-Feinberg, Aurora, Carden, Kirsch, Kristo, Malhotra, Martin, Olson, Ramar and Gurubhagavatula2020), light pollution (Hölker et al., Reference Hölker, Moss, Griefahn, Kloas, Voigt, Henckel, Hänel, Kappeler, Völker, Schwope, Franke, Uhrlandt, Fischer, Klenke, Wolter and Tockner2010), blue light from devices that disrupt sleep (Hatori et al., Reference Hatori, Gronfier, Van Gelder, Bernstein, Carreras, Panda, Marks, Sliney, Hunt, Hirota, Furukawa and Tsubota2017), and labor practices that affect sleep (Grzywacz et al., Reference Grzywacz, Casey and Jones2007). Moreover, inadequate sleep is not a problem that is confined to the United States—it is a global problem (Chattu et al., Reference Chattu, Manzar, Kumary, Burman, Spence and Pandi-Perumal2019), as are sleep inequalities by socioeconomic status (Bessone et al., Reference Bessone, Rao, Schilbach, Schofield and Toma2021).
In short, political scientists across subfields can and should consider whether and how sleep influences political life in their area of expertise. This novel paradigm presents an opportunity for discovery of new phenomena and links across areas of research and practice. Examining this vital behavior across the range of political science subfields can help us to develop a holistic picture of the political consequences of sleep. This new research agenda will enrich our theories of politics and enable us to identify pressing areas for policy interventions to sustain our democracy.
