The 3rd UN World Conference on
Disaster Risk Reduction in Sendai	Psychological factors in rumor propagation
after the Great East Japan Earthquake
Yuko Tanaka
Project Researcher
Research Organization of Information and Systems
National Institute of Informatics

Sendai, March 17, 2015

Summary of Rumor Psychologyv Prasad (1935) in British Journal of Psychology– found that in the past 1,000 years the same types of rumors
related to earthquakes appear again and again in different
locations.

v Rumor studies have revealed psychological factors that
affect rumor spreading behavior– Anxiety, Accuracy, Importance (Anthony, 1973; DiFonzo & Bordia, 2000;
Rosnow, 1991; Walker & Beckele, 1987)v Nevertheless, false rumors still circulate– 2008: Sichuan earthquake – the Internet (Sun, Jin, & Gao, 2009)– 2010: Haiti and Chile earthquakes – social media (Mendora & Poblete,2010; Oh, Kwon, & Rao, 2010)– 2011: Great East Japan Earthquake
Y.	  Tanaka	  (NII/ROIS)	  2013.11.20	  2

Mechanism of Rumor Occurrencev Mikami (1986)– Rumors occur and spread, because people try tointerpret ambiguous situations in an emergent
situation– When an earthquake occurs…
à shaking is perceivedà peacetime definition of “situation” collapsesà ambiguous situations occurà additional info is sought to understand the situation
demand– Information shortages creates a gap
between supply and demand

supplyGap– Rumors occur to fill the gap
3thousandProblems Caused by Social Media
Twitter

The number of social media users in Japan(http://www.netratings.co.jp/nielsen_wire/jp/2011/06/28/sns_201105.pdf)v The number of social media users increased after theearthquake.
– Social media played an important role in sharing informationand coordinating disaster response.
4Order matters…

Rumor

Criticism
Rumor

Rumor
Stoppers

Rumor
Spreaders

32% 68%Rumor
Stoppers

Rumor
Spreaders

49% 51%

Tanaka,	  Y.,	  Sakamoto,	  Y.,	  &	  Matsuka,	  T.	  (2013).	  Toward	  a	  Social-­‐Technological	  System	  that	  Inactivates	  False	  Rumors	  through	  the	  Critical	  Thinking	  of	  Crowds.	  In	  Proceedings	  of	  the	  46th	  Hawaii	  International	  Conference	  on	  System	  Sciences,	  IEEE,	  pp.	  649–658.	  	  	  5Critical Thinking of Crowdsv Many people tried to stop the spread of false
rumors by criticizing the rumor tweets.
– Not only the government officials and experts but also
many laypeople posted criticism tweets.

Where	  is	  the	  evidence?	  Without	  it,	  this	  tweet	  is	  just	  a	  rumor.	  	  RT@kobayashiasao:	  A	  big	  earthquake	  warning	  has	  been	  announced.	  The	  earthquake	  will	  hit	  within	  48	  hours.	  It	  will	  be	  over	  M7.	  	

6Order matters…

Rumor
Criticism
Rumor
Stopper

Rumor
Spreader

32% 68%

Criticism
Socialtechnologicaldesign	RumorRumor
Stopper

Rumor
Spreader49% 51%
Exposure to criticisms increased
the proportion of rumor-stopping responses 7

Practical Implicationv Rumor will never disappear…
• To understand ambiguous situations• Rumors look accurate, important, and rise anxietyv However, we can minimize the negative impacts…
• Design a social-technological environment has thepotential to inactivate false information.
– Exposure to criticisms increased the proportion of rumorstopping responses• Design attentions based on understanding
psychological reasons.
Check evidence
before the clickAttention by AC	

Distinguish GUESS
from FACT8Referencesv Anthony, S. Anxiety and Rumor. The Journal of Social Psychology, 89(1), 1973, 91–98.
v Difonzo, N. and Bordia, P. How top PR Professionals Handle Hearsay: CorporateRumors, Their Effects, and Strategies to Manage Them. Public Relations Review,26(2), 2000, 173–190.
v Mendoza, M. and Poblete, B. Twitter Under Crisis: Can We Trust What We RT? In
Proceedings of the First Workshop on Social Media Analytics, 2010, 71–79.
v Oh, O., Kwon, K. H., and Rao, H. R. An Exploration of Social Media in Extreme
Events: Rumor Theory and Twitter during the Haiti Earthquake 2010. In Proceedingsof the International Conference on Information Systems (ICIS), 2010, 231v Prasad, J. The Psychology of Rumor: A Study relating to the Great Indian Earthquakeof 1934. British Journal of Psychology: General Section, 26(1), 1935, 1–15.
v Rosnow, R.L. Inside Rumor: A Personal Journey. American Psychologist, 46(5),1991, 484–496.
v Sun, J., Jin, S., and Cao, S. A Qualitative Psychological Analysis of the Rumors
Appeared after A Disaster: The Evidence from the Rumors Appeared after “5·12Wenchuan Earthquake”. Advances in Psychological Science, 17(3), 2009, 602–609.
v Walker, C.J. and Beckerle, C.A. The Effect of State Anxiety on Rumor Transmission.
Journal of Social Behavior and Personality, 2(3), 1987, 353-360.

Y.	  Tanaka	  (NII/ROIS)	  2013.11.20	  9