Via The Conversation: Recovering from disasters: Social networks matter more than bottled water and batteries. Why some communities lost fewer lives than others in the Tohoku earthquake/tsunami of 2011: more social capital Excerpt:
A Japanese colleague and I hoped to learn why the mortality rate from the tsunami varied tremendously. In some cities along the coast, no one was killed by waves which reached up to 60 feet; in others, up to ten percent of the population lost their lives.
We studied more than 130 cities, towns and villages in Tohoku, looking at factors such as exposure to the ocean, seawall height, tsunami height, voting patterns, demographics, and social capital. We found that municipalities which had higher levels of trust and interaction had lower mortality levels after we controlled for all of those confounding factors.
The kind of social tie that mattered here was horizontal, between town residents. It was a surprising finding given that Japan has spent a tremendous amount of money on physical infrastructure such as seawalls, but invested very little in building social ties and cohesion.
Based on interviews with survivors and a review of the data, we believe that communities with more ties, interaction and shared norms worked effectively to provide help to kin, family and neighbors. In many cases only 40 minutes separated the earthquake and the arrival of the tsunami. During that time, residents literally picked up and carried many elderly people out of vulnerable, low-lying areas. In high-trust neighborhoods, people knocked on doors of those who needed help and escorted them out of harm’s way.