The sleep deficit epidemic and increasing loneliness in the U.S. may be more interconnected than previously thought. Loneliness and social isolation can cause sleep disruption, and the reverse also holds true. A research group found that sleep deprivation causes biological changes that lead to social withdrawal (Simon 2018). Not only does sleep impact our physical and mental health, it also determines how we interact with others.
Simon and colleagues tested multiple aspects of socialization. After a night of deprivation or adequate rest, participants were tested on how much distance they maintained from others approaching. They conducted this study in-person and in a computerized stimulation, during which the participants’ neural activity was monitored on an fMRI. Brain imaging analysis focused on networks associated with social interactions, such as the theory-of-mind (TOM) network, which infers the intentions of others. Researchers also analyzed the Near Space network, which maps other humans approaching to warn of potential threats. Participants were interviewed and then their sociality was rated by blinded judges. The researchers did a second study with online self-reports to test if small changes in sleep quality predicted loneliness the next day. For two days, participants kept a log of their sleep and social behavior.
The findings support the hypothesis that sleep disruption is correlated with social isolation. For both the in-person and computerized version of the first experiment, participants maintained more distance from others after just one night of sleep deprivation. In the second experiment, lower sleep efficiency one night was associated with higher loneliness the next day. Both drastic changes (deprivation in the lab) and natural variations (sleep logs at home) in sleep quality impacted social behavior.
To explain this socially aversive behavior, researchers turned to brain imaging. fMRI scans showed that sleep deficit reduced activity in the TOM network, so participants were less likely to understand the intentions of others. Sleep deprivation increased activity in the Near Space network, making participants more reactive to a person advancing towards them. Judges who watched interviews of sleep-deprived participants perceived the individuals as more lonely, and the judges felt less compelled to interact with them.
Overall, sleep deprivation causes hypersensitivity in the neural regions that warn of a threatening intruder and result in the impairment of neural regions that promote the understanding of others. This creates a domino effect on social behavior because the change in neural activity leads individuals to withdraw from others. Outsiders perceive the individual as lonely and refrain from interacting with them, thus creating a vicious cycle in which social withdrawal deters others and compounds isolation.
The relationship between sleep and social interaction implies dire consequences for groups with more sleep problems, such as women, shift workers, and marginalized ethnicities. Isolation from others increases risk of countless health problems along with premature death, alcoholism, and suicide. Even groups with more temporary sleep disruption are impacted: for college students who regularly pull all-nighters, sleep loss can exert unseen consequences on their social life. Sleep deprivation has cascading effects on mental health and well-being, which in turn jeopardize healthy socialization.
Tulsi, Atharva. “Silhouette of Person Standing on Concrete Road with Streetlights Turned on during Nighttime.” Unsplash, 21 Feb. 2018, unsplash.com/photos/Uv2BaNZjjvY/info. Accessed 21 Apr. 2021.
Simon, Eti Ben, and Matthew P. Walker. "Sleep loss causes social withdrawal and loneliness." Nature communications 9.1 (2018): 1-9.