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  • Inadequate sleep is a common problem and is linked to an increased risk of physical and mental health problems.
  • A new study shows that sleep deprivation and poor sleep quality are associated with a decreased desire to help others.
  • The study also indicates that the potential loss of 1 hour of sleep due to daylight savings time is associated with a reduction in the amount of money donated to a national charity.
  • The findings underscore the importance of sleep hygiene in the maintenance of helping or prosocial behaviors in addition to physical and mental health.

More than 1 in 3 individuals in the United States report less than the minimum recommended sleep duration of 7 hours of sleep per night.

Insufficient sleep is a pervasive problem associated with a number of negative health outcomes. Studies have found that insufficient sleep is associated with an increased risk of:

Moreover, inadequate or poor sleep can also adversely impact mental health, including an increase in symptoms of depression, anxiety, and irritability, and a reduced ability to regulate emotions.

Whether sleep quantity or quality can influence prosocial behaviors, which are behaviors that benefit others, has not yet been fully established.

New research published in the journal PLOS Biology reveals that lacking quality sleep may reduce the willingness of individuals to help others.

“It is time as a society to abandon the idea that sleep is unnecessary or a waste of time and, without feeling embarrassed, start getting the sleep that we need” Dr. Eti Ben Simon, a sleep researcher at the University of California, Berkeley and co-author of the new study, told Medical News Today. “It is the best form of kindness we can offer ourselves, as well as the people around us.”

Prior research has linked poor sleep to deficits in emotional processing, which could potentially reduce prosocial behaviors.

Other studies have shown that inadequate sleep results in decreased activity in brain regions involved in empathy and prosocial behaviors like voting. This includes brain regions involved in social cognition, which is the ability to process social information and respond appropriately to social situations.

In the present study, the researchers conducted three different experiments to examine the effects of sleep on prosocial behavior at the individual, group, and societal levels. In the first experiment, the researchers examined the impact of sleep deprivation on helping behavior within the same individual.

To evaluate changes in helping behavior, the researchers used a questionnaire assessing the willingness of the participants to help others in everyday situations, such as helping a stranger with directions or carrying groceries.

The researchers assessed the helping behavior of the same participants on 2 separate days. On one of the days, the participants were administered the questionnaire after being awake for 24 hours. In the other instance, the participants had a night’s sleep before responding to the questionnaire.

Study participants showed a decline in the desire to help others after being sleep deprived than after being rested.

This decline in the willingness to help others persisted after controlling for non-social factors impacted by sleep deprivation, including attention, motivation to engage in effortful behavior, and mood.

Following the questionnaire portion of the study, the researchers used functional MRI (fMRI) imaging to examine the impact of sleep loss on brain regions involved in prosocial behaviors.

The researchers found that sleep deprivation was associated with reduced activity in brain regions involved in social cognition while performing a social task.

Significantly, the decline in helping behavior due to sleep loss was positively correlated with the magnitude of the decline in activity in the brain regions involved in social cognition. The results suggest that the effects of sleep deprivation on prosocial behavior were mediated by these brain regions.

“This study builds on other recent research to suggest that the societal costs of poor sleep hygiene are greater than previously thought,” Dr. David Dickinson, PhD, a sleep researcher and professor of economics at Appalachian State University, not involved in the study, told MNT.

“[It] is especially important to show the negative impacts of insufficient sleep on giving behaviors because such behaviors contribute to the ‘social capital’ of society, and this social capital can have multiplier effects in an economy.”

– Dr. David Dickinson, PhD, sleep researcher and economics professor

Although the initial experiment demonstrated that a lack of sleep could reduce helping behavior, sleep deprivation is not a regular occurrence.

Hence, in the subsequent experiment, the researchers recruited a group of 171 participants online to examine whether the natural variation in night-to-night sleep had an impact on the desire to help others on the following day.

The participants maintained sleep diaries for 4 nights and were asked to respond to an online questionnaire after each night to evaluate helping behavior.

The researchers found that a decline in sleep quality, measured as the fraction of time spent sleeping out of the total time spent in bed, was associated with a lower desire to help others.

Interestingly, the willingness to help others was not associated with the total time spent sleeping.

The results from the first experiment showed that at least some sleep is necessary for maintaining helpful behavior. Furthermore, the second experiment shows that after receiving a certain minimum amount of sleep, sleep quality may have a larger impact on helping behavior than sleep duration.

The third experiment examined the real-world impact of the loss of sleep on helping behavior at the national level.

Using data on monetary donations made to an online national charity between 2001 and 2016, the researchers examined whether the potential loss of an hour of sleep during daylight savings time influenced the donation amount.

In comparison to the weeks before and after daylight savings time, there was a reduction in the donation amounts during the week of the transition to daylight savings time.

Moreover, a decrease in donation amounts during the transition to daylight savings time was absent in states that do not observe daylight savings time, like Arizona and Hawaii.

Thus, while the initial two experiments showed a decline in the willingness to help others, the analysis of data on monetary donations demonstrates the real-world impact of the loss of even a single hour of sleep on prosocial behaviors.

Highlighting the thorough experimental design used by the study’s authors, Dr. Dickinson said:

“By bringing multiple approaches to bear on the question and showing that using different samples and data sources all point to a common core finding (or highlighting the neural mechanism at work in the key behavioral finding), it should give the reader more confidence that this result is not an artifact of a single study, data source, or methodology.”

The researchers note that this is the first study to establish a link between sleep and helping behaviors. Future studies will need to further clarify the role of sleep in prosocial behaviors.

Other studies have also shown an association between sleep and social capital, a measure of social cohesiveness. This highlights the importance of social policies and education that promote sleep hygiene.

Dr. Rohit Budhiraja, director of the Sleep and Circadian Disorders Clinic at Brigham and Women’s Hospital in Boston, not involved in the study, told MNT:

“The authors suggest that the impact of insufficient sleep on helping was likely not related to the changes in mood or empathy or desire to act.”

“While [the study authors] performed notable tests to exclude other factors and establish a direct impact of sleep deprivation on a decreased desire to help, the limitations of methodology prevent a complete exclusion of these variables as confounders. Nonetheless, the study provides further evidence regarding the negative impacts of sleep deprivation and the need to get adequate sleep.”

– Dr. Rohit Hudhiraja, director of the Sleep and Circadian Disorders Clinic at Brigham and Women’s Hospital

In addition, cultural factors and personality traits may also influence a person’s propensity toward helping behaviors, but the impact of these factors can be hard to qualify.

Of course, regardless of any underlying factors, sleep quantity and quality can be improved by practicing good sleep hygiene and getting sufficient rest at night.