The Biggest Psychological Experiment in History Is Running NowNEWS | 14 October 2025The impact of COVID-19 on the physical health of the world's citizens is extraordinary. By mid-May there were upward of four million cases spread across more than 180 countries. The pandemic's effect on mental health could be even more far-reaching. At one point roughly one third of the planet's population was under orders to stay home. That means 2.6 billion people--more than were alive during World War II--were experiencing the emotional and financial reverberations of this new coronavirus. "[The lockdown] is arguably the largest psychological experiment ever conducted," wrote health psychologist Elke Van Hoof of Free University of Brussels-VUB in Belgium. The results of this unwitting experiment are only beginning to be calculated.
The science of resilience, which investigates how people weather adversity, offers some clues. A resilient individual, wrote Harvard University psychiatrist George Vaillant, resembles a twig with a fresh, green living core. "When twisted out of shape, such a twig bends, but it does not break; instead it springs back and continues growing." The metaphor describes a surprising number of people: As many as two thirds of individuals recover from difficult experiences without prolonged psychological effects, even when they have lived through events such as violent crime or being a prisoner of war. Some even go on to grow and learn from what happened to them. But the other third suffers real psychological distress--some people for a few months, others for years.
Even if most individuals prove resilient, the toll of the COVID-19 disruptions and the sheer numbers involved have experts warning of a mental illness "tsunami." People face a multiple wallop: the threat of disease, loneliness of isolation, loss of loved ones, repercussions of job loss and ongoing uncertainty about when the pandemic will end. Depression, anxiety and post-traumatic stress will undoubtedly follow for some. Mental health hotlines are reporting surges in calls, and early surveys have found high levels of concern. "This pandemic just ticks all the boxes in terms of the kinds of stressors that are going to be difficult," says psychologist Anita DeLongis of the University of British Columbia, who studies psychosocial responses to disease. The deaths by suicide of health care professionals who had been on the medical front lines are powerful reminders of the risks.
Individual resilience is further complicated by the fact that this pandemic has not affected each person in the same way. For all that is shared--the coronavirus has struck every level of society and left few lives unchanged--there has been tremendous variation in the disruption and devastation experienced. Consider Brooklyn, just one borough in hard-hit New York City. Residents who started the year living or working within a few miles of one another have very different stories of illness, loss and navigating the challenges of social distancing. How quickly and how well individuals, businesses and organizations recover will depend on the jobs, insurance and health they had when this started, on whether they have endured hassle or heartbreak, and on whether they can tap financial resources and social support.
The pandemic has laid bare the inequities in the American health care system and economic safety net. Black and Latino Americans are dying at much higher rates than white Americans. "When we talk about preexisting conditions, it isn't just if I'm obese, it's our society's preexisting condition," says medical anthropologist Carol Worthman of Emory University, an expert in global mental health.
Fortunately, the unprecedented pandemic is leading to unprecedented science not just in virology but on mental health and resilience. Behavioral scientists are measuring the psychological toll in real time and striving to identify what helps people cope. Unlike, say, the September 11 terrorist attacks or Hurricane Katrina, which occurred over a finite period even though their effects were drawn out, the open-ended time frame for COVID-19 allows for new kinds of longitudinal studies and research directions. The sudden mass switch to virtual forms of working and socializing is expected to jump-start more nuanced investigations into what makes social interaction satisfying--or stultifying. If researchers meet the challenge of COVID-19, says psychiatrist Dennis Charney of the Icahn School of Medicine at Mount Sinai, "there will be a whole new science of resilience. We could learn how to help people become more resilient before these things happen."
Bernell Grier ( also shown at top ), who leads a community development corporation in Brooklyn, N.Y., is helping black people affected by the pandemic.
Bend but Don't Break
Rafael Hasid arrived in New York City from his native Israel in 2000 to attend the French Culinary Institute. In 2005 he opened a restaurant called Miriam in Brooklyn that became a neighborhood favorite. In the first weeks of March Hasid could see what was coming. "I was following the news in Israel," he says. "We were two weeks behind in every respect. I was saying, 'This is going to happen here.'" When Miriam's popular weekend brunch attracted a third of the usual crowd, Hasid did not spend much time wondering what to do: he gave away all of the restaurant's perishable food to the neighbors. By the time the city required all restaurants to shut down, Miriam had already closed.
Faced with potentially traumatic events, "about 65 percent of people are going to show minimal psychological symptoms," says clinical psychologist George Bonanno of Teacher's College at Columbia University. Bonanno, who is an expert on resiliency, studies the aftermath of hurricanes, terrorist attacks, life-threatening injuries and epidemics such as the 2003 SARS outbreak. His research and that of others consistently show three common psychological responses to hardship. Two thirds of people follow a resilience trajectory and maintain relatively stable psychological and physical health. About 25 percent struggle temporarily with psychopathology such as depression or post-traumatic stress disorder and then recover--a pattern known as the recovery trajectory. And 10 percent suffer lasting psychological distress. These results hold true across diverse populations and socioeconomic statuses. "We're talking about everybody," Bonanno says. On the other hand, the risk of psychiatric disorders is twice as high for people on the lowest economic rungs.
But the mental health effects of a crisis so sweeping and insidious may not adhere to this paradigm. Studies show that strict quarantine can lead to negative psychological effects such as PTSD, although few of us have been under true quarantine, which refers to isolating after a possible exposure to infection. Instead much of the world is living with restrictions that Bonanno suspects amount to something more like managing constant stress. "This is the first time in living history we've had a global lockdown that's gone on for such a long time," says epidemiologist Daisy Fancourt of University College London. "We simply don't know how people are going to react to this."
The potential scope of the impact is considerable. "This is different from other forms of stress because it's not just one domain of your life," says health psychologist Nancy Sin of the University of British Columbia. "People are dealing with relationship or family challenges, with financial and work challenges, with health."
Early reports are already showing clear effects. The first nationwide large-scale survey in China, where the crisis hit earliest, found that almost 35 percent reported psychological distress. In the U.S., rising fear and anxiety about COVID have been found in people who already suffer from anxiety. Another study captured worrisome findings in older adults. This is surprising because previous research shows that, for the most part, older adults have better emotional well-being. "During this pandemic, older adults don't have those age-related strengths in emotions that we would typically expect," says Sin, who studies aging and is collaborating with DeLongis in an ongoing COVID-19 study of 64,000 individuals worldwide. "They are reporting just as much stress as middle-aged and younger people."
Sin is still analyzing the causes of the stress but suspects it is caused by older adults' higher likelihood of getting sick and of losing loved ones. Older people are coping with their stress better than younger people, however, and reporting less depression or anxiety. They may be benefiting from the perspective that comes with having lived through more than younger people, Sin says. Adults older than 65 have also had more time to develop skills for dealing with stress, and many have retired and so are less likely to be concerned about work.
Fancourt began a study in mid-March that grew to include more than 85,000 U.K. residents. It is tracking depression, anxiety, stress and loneliness week by week. "We need to know in real time what's happening," Fancourt says. Six weeks in, they found that levels of depression were significantly higher than before the pandemic.
Generally, those with previously diagnosed mental health illnesses, those who live alone and younger people were reporting the highest levels of depression and anxiety. On the positive side, there was a slight decrease in anxiety levels once the lockdown was declared. "Uncertainty tends to make things worse," Fancourt says. Some are frozen by not knowing what is to come, whereas others find ways to carry on.
After Hasid's restaurant had been closed for three weeks, he had not yet received any of the government payments meant to protect small businesses. While his situation was rife with uncertainty, "I was thinking that we have to continue creating business for ourselves," he says. When a few customers e-mailed to inquire if he would consider catering their Passover seders, Hasid developed a prix fixe holiday menu for delivery. Before the pandemic, Hasid was planning to open a delicatessen that would be located in an adjacent storefront. Instead of renovating the new space, he opened the deli inside the restaurant. His biggest worry was whether employees would feel safe. To reassure them, in addition to social distancing, he requires masks and gloves and has someone come in to bleach the restaurant morning and night. Hasid is looking into other sanitizing strategies involving blowers and alcohol that he heard have been used in Singapore.
Hasid recognizes that his ability to adapt is not something every business can do, especially many restaurants that run on tight margins. The new operation is using minimal staff, but Hasid continues to pay--out of his own pocket--any employees who have not been able to get through to unemployment. Serving food via delivery brings in less than a third of Miriam's former income, but he says it is better than nothing. The restaurant is also preparing a weekly meal for a local hospital. "It is not a money maker, but it's the least we can do." Hasid is pleased with Miriam's reinvention and optimistic that the restaurant will ultimately survive. "We are in a much better situation than a lot of other places in New York," he says.Author: Martin Krzywinski. Lydia Denworth. Photographs Ethan Hill. Interviews Jillian Mock. Jen Schwartz. Charles Schmidt. Mark Fischetti. Source
