Poor Sleep and Reactive Aggression: Results from a National Sample of African American Adults

Background/purpose: We know that poor sleep can have important implications for a variety of health outcomes and some evidence suggests a link between sleep and aggressive behavior.  However, few studies have looked at this relationship among African-Americans in the United States. The impact of sleep on behavior may have a disproportionate effect on African Americans, who have been consistently shown to have higher chronic and acute stress levels than Caucasians. Given the heightened stressors confronted by African Americans, including their extensive experiences of discrimination and greater involvement in violence in the aggregate, we hypothesize that poor sleep quality and shorter sleep duration will be associated with increased likelihood of reactive aggression.

Methods: Data from the National Survey of American Life (NSAL) and the NSAL Adult Re-Interview were used to examine associations between sleep duration and self-reported quality of sleep on reactive aggression among African American and Caribbean Black respondents between the ages of 18 and 65 (n = 2,499). Reactive aggression (0 = no, 1 = yes) was measured on the basis of respondent self-report: “I lose my temper and get into physical fights”. Sleep was assessed based on the number of hours of actual sleep on average study respondents reported.  Items relating to difficulty initiating sleep, paralysis, and dissatisfaction as well as measures of perceived discrimination and difficulty reducing stress were also employed.  Logistic regression analyses were conducted to examine the relationship between sleep and reactive aggression. We also conducted bivariate and multivariate analyses to examine the relationship between stress-related factors and sleep-related problems identified as significantly associated with reactive aggression. 

Results: After controlling for an array of sociodemographic and psychiatric factors, sleep was found to be significantly associated with reactive aggression.  Specifically, individuals who reported sleeping on average less than five hours per night were nearly three times more likely to report losing their temper and engaging in a physical fight (AOR = 3.13, 95% CI = 1.22-8.02).  Moreover, individuals who reported being "very dissatisfied" with their sleep were more than two times more likely to report losing their temper and engaging in physical fights (AOR = 3.32, 95% CI = 1.50-7.33). Persons reporting everyday discrimination and problems managing stress were more likely to sleep poorly.

Conclusions: The present study is among the first to document an association between poor sleep and reactive violence among African-Americans.  Findings suggest that reducing discrimination may lead to improved sleep and subsequently reduce forms of reactive violence. Study results also converge with research that suggests impaired sleep resulting from stress activation reduces pre-frontal cortical functioning that restricts blood flow which in turn reduces the capacity for behavioral inhibition and increases the instability in emotional responding. Improving sleep among vulnerable populations is likely to possess broad positive effects possibly including reducing aggression.