How to Survive a Tsunami: An Individualistic Maxim in Japanese Collectivism
The Ministry of Land, Infrastructure, Transport and Tourism of Japan conducted the survey of evacuation behavior among the survivors of the 2011 tsunami (MLIT 2012, N=10,603). Based on this data, we will explore three characteristics of evacuation heuristics.
(1) Priority of intuitive judgement as a trigger of evacuation behavior to tsunami alert.
(2) Strong bystander effects occur after the M9 earthquake.
(3) Gathering information, protection of one’s family, and serving group mission are typical behavior to delay the time to start evacuation.
“Tsunami-Tendenko” (running to a higher ground by oneself, without finding family members) is known as an individualistic maxim of tsunami evacuation in northeast region (Katada 2014). Nominally, it inhibits us from helping our family members, but it maximizes the number of survivors by reducing the double contingency risk of deciding whether to help family members or not. In addition, the maxim emphasizes the preparedness against tsunami. Cooperation and trust must be prepared before tsunami, not during tsunami.