In the aftermath of the 2011 tsunami, studies show that how people are relocated can affect their recovery

By

SUSAN PINKER

Aug. 17, 2017 10:21 a.m. ET

See the column on the Wall Street Journal site

Twelve years ago this month, Hurricane Katrina devastated New Orleans and much of the rest of the Gulf Coast, killing some 1,500 people and displacing more than a million others. Six years later, when an earthquake and tsunami hit eastern Japan in 2011, about 18,500 people lost their lives, and another 345,000 lost their homes, some permanently.

Researchers have found that disaster survivors often suffer from a range of long-term mental and physical problems. Daniel Aldrich of Northeastern University has shown, for example, that those forced to relocate subsequently experience higher rates of depression and divorce. Survivors of the Japanese tsunami were found to have a sharply higher rate of cognitive decline for their population, according to researchers at the Harvard T.H. Chan School of Public Health and several Japanese universities.

For those concerned about responding more effectively to future catastrophes, the question is whether it is possible to prevent such negative effects. Scientists studying the Japanese tsunami now seem to have discovered at least part of the solution: It turns out that howpeople are moved after a disaster has a big impact on their social relationships and, ultimately, on their health.

The findings, reported last month in the journal Science Advances, emerged by “pure serendipity,” according to Ichiro Kawachi, the lead author of the new study who had worked on the earlier cognitive-decline paper.

In 2010, Prof. Kawachi, an epidemiologist at the T.H. Chan School of Public Health, along with his postdoctoral fellow Hiroyuki Hikichi and several colleagues, launched a study in Japan focused on the predictors of healthy aging. The researchers sent detailed questionnaires about lifestyle and social habits to everyone over age 65 in 20 Japanese municipalities. Seven months later the tsunami hit. By then, the researchers had extensive data on about 3,420 people in the Miyagi Prefecture, a densely inhabited area about 50 miles from the disaster’s epicenter.

Of these people, 175 had to be permanently resettled, because their homes were destroyed. First they had to endure “stressful living situations in school gyms, where there were few toilets and no privacy. People were in a hurry to get out of there,” said Prof. Kawachi. To get to the next stage, for more permanent housing, individual survivors could either sign up for a lottery that gave winners access to the front of the line for trailers or could wait and move into emergency shelters as a neighborhood or group. Ultimately, everyone ended up in the same remote, unheated and rather dismal type of shelter.

Two and a half years after the disaster, the researchers again reached out to the survivors. The 96 people who had relocated on their own, the researchers learned, ended up with an impoverished social life. Compared with their pre-tsunami lives, they met less with friends and joined in fewer civic and leisure activities. They were also less likely to support other people or get help themselves. The disaster had effectively stranded them.

In comparison, the 79 people who relocated as a group preserved and enhanced their patterns of informal socializing, not only with friends, but also in how they engaged with the community—in sports, church, hobbies or volunteering. The researchers were careful to control for any independent effect that people’s personality traits or other factors might have had on the results.

The upshot? The weight of evidence shows that disaster-response managers should focus less on speed, sea walls and sandbags and more on preserving people’s social ties, says Prof. Aldrich, who has studied both the Japanese and Gulf Coast catastrophes. “After Katrina, people were put on a bus and not told where they were going. When they arrived they were told, ‘Welcome. You’re living in Arkansas now.’ ”

Prof. Kawachi agrees. “Losing contact with neighbors…hastens dementia and loss of physical function. An underappreciated aspect of disaster policy is that human relations matter as much as giving out timely aid.”