Sleep tight and don't let the socioeconomic inequality bite! Relations between social class, sleep, and mental and physical health

Social class affects many aspects of our daily lives, including how we talk, what we eat, and what clothes we wear (Cote, 2011). A substantial body of research indicates that people from lower social classes tend to have poorer health than people from higher social classes (e.g., Adler & Ostrove, 1999; Euteneuer, 2014). Several different explanations of this relationship have been explored such as social support, physical activity, self-efficacy, diet quality, and caffeine. This thesis aims to highlight the effect of social class on health through an under-studied mechanism: sleep. Specifically, the thesis investigated sleep as a mediator of the negative association between social class and health problems. All four studies (Study 1, N = 372; Study 2, N = 376; Study 3, N = 628; Study 4, N = 446) involved quantitative online self-report surveys conducted with undergraduate university and Hunter Technical and Further Education (TAFE) students. The results revealed that sleep quality, sleep duration, sleep disturbances, presleep worries, and sleep schedule variability mediated the relationship between social class and physical and mental health. These mediation effects occurred even when controlling for a wide range of covariates, such as age, gender, relationship status, and eveningness. These results imply that sleep may help to explain social class differences in health, and they highlight the importance of addressing sleep issues in lower class individuals. When the sleep measures were compared directly, I found that sleep quality and presleep worries were the strongest and most independent mediators across my four studies. Importantly, the mediation effect of sleep was as strong as or stronger than other possible mediators of the relation between social class and health. In addition, my final study indicated that when trying to improve sleep, it is important to consider interventions that are accessible for people of all classes.