Social distancing, or physical distancing, is a set of non-pharmaceutical interventions or measures taken to prevent the spread of a contagious disease by maintaining a physical distance between people and reducing the number of times people come into close contact with each other. It involves keeping a distance of six feet or two meters from others and avoiding gathering together in large groups.

During the 2019–2020 coronavirus pandemic, the World Health Organization (WHO) suggested the reference to “physical” as an alternative to “social”, in keeping with the notion that it is a physical distance which prevents transmission; people can remain socially connected via technology. To slow down the spread of infectious diseases and avoid overburdening healthcare systems, particularly during a pandemic, several social distancing measures are used, including the closing of schools and workplaces, isolation, quarantine, restricting movement of people and the cancellation of mass gatherings.

Social distancing measures are more effective when the infectious disease spreads via droplet contact (coughing or sneezing); direct physical contact, including sexual contact; indirect physical contact (e.g., by touching a contaminated surface); or airborne transmission (if the microorganism can survive in the air for long periods). The measures are less effective when an infection is transmitted primarily via contaminated water or food or by vectors such as mosquitoes or other insects. Drawbacks of social distancing can include loneliness, reduced productivity and the loss of other benefits associated with human interaction.

The Centers for Disease Control and Prevention (CDC) have described social distancing as a set of “methods for reducing frequency and closeness of contact between people in order to decrease the risk of transmission of disease”. During the 2019–2020 coronavirus pandemic, the CDC revised the definition of social distancing as “remaining out of congregated settings, avoiding mass gatherings, and maintaining distance (approximately six feet or two meters) from others when possible.” Knowing that disease is circulating may trigger a change in behavior by people choosing to stay away from public places and other people. When implemented to control epidemics, such social distancing can result in benefits but with an economic cost. Research indicates that measures must be applied rigorously and immediately in order to be effective. Several social distancing measures are used to control the spread of contagious illnesses.

Keeping at least two-meter (six-foot) distance from each other and avoiding hugs and gestures that involve direct physical contact, reduce the risk of becoming infected during flu pandemics and the coronavirus pandemic of 2020. These distances of separation, in addition to personal hygiene measures, are also recommended at places of work. Where possible it may be recommended to home. Modeling studies based on U.S. data suggest that if 10% of affected workplaces are closed, the overall infection transmission rate is around 11.9% and the epidemic peak time is slightly delayed. In contrast, if 33% of affected workplaces are closed, the attack rate decreases to 4.9%, and the peak time is delayed by one week. Workplace closures include the closure of “non-essential” businesses and social services (“non-essential” means those facilities that do not maintain primary functions in the community, as opposed to essential services).

Cancellation of mass gatherings includes sports events, films or musical shows Evidence suggesting that mass gatherings increase the potential for infectious disease transmission is inconclusive. Anecdotal evidence suggests certain types of mass gatherings may be associated with increased risk of influenza transmission, and may also “seed” new strains into an area, instigating community transmission in a pandemic. During the 2019–2020 coronavirus pandemic, social distancing and related measures were emphasized by several governments as alternatives to an enforced quarantine of heavily affected areas. According to UNESCO monitoring, more than a hundred countries have implemented nationwide school closures in response to COVID-19, impacting over half the world’s student population.

These preventive measures such as social-distancing and self-isolation prompted the widespread closure of primary, secondary, and post-secondary schools in more than 120 countries. Widespread media coverage about a pandemic, its impact on the economy, and resulting hardships may create anxiety. Change in daily circumstances and uncertainty about the future may add onto the mental stress of being away from other people.