A Caltech Library Service

Honesty mediates the relationship between serotonin and reaction to unfairness

Takahashi, Hidehiko and Takano, Harumasa and Camerer, Colin F. and Ideno, Takashi and Okubo, Shigetaka and Matsui, Hiroshi and Tamari, Yuki and Takemura, Kazuhisa and Arakawa, Ryosuke and Kodaka, Fumitoshi and Yamada, Makiko and Eguchi, Yoko and Murai, Toshiya and Okubo, Yoshiro and Kato, Motoichiro and Ito, Hiroshi and Suhara, Tetsuya (2012) Honesty mediates the relationship between serotonin and reaction to unfairness. Proceedings of the National Academy of Sciences of the United States of America, 109 (11). pp. 4281-4284. ISSN 0027-8424. PMCID PMC3306703. doi:10.1073/pnas.1118687109.

PDF - Published Version
See Usage Policy.

PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


How does one deal with unfair behaviors? This subject has long been investigated by various disciplines including philosophy, psychology, economics, and biology. However, our reactions to unfairness differ from one individual to another. Experimental economics studies using the ultimatum game (UG), in which players must decide whether to accept or reject fair or unfair offers, have also shown that there are substantial individual differences in reaction to unfairness. However, little is known about psychological as well as neurobiological mechanisms of this observation. We combined a molecular imaging technique, an economics game, and a personality inventory to elucidate the neurobiological mechanism of heterogeneous reactions to unfairness. Contrary to the common belief that aggressive personalities (impulsivity or hostility) are related to the high rejection rate of unfair offers in UG, we found that individuals with apparently peaceful personalities (straightforwardness and trust) rejected more often and were engaged in personally costly forms of retaliation. Furthermore, individuals with a low level of serotonin transporters in the dorsal raphe nucleus (DRN) are honest and trustful, and thus cannot tolerate unfairness, being candid in expressing their frustrations. In other words, higher central serotonin transmission might allow us to behave adroitly and opportunistically, being good at playing games while pursuing self-interest. We provide unique neurobiological evidence to account for individual differences of reaction to unfairness.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle Information
Camerer, Colin F.0000-0003-4049-1871
Additional Information:© 2012 by the National Academy of Sciences. Freely available online through the PNAS open access option. Edited by Ranulfo Romo, Universidad Nacional Autónoma de México, Mexico City, D.F., Mexico, and approved January 19, 2012 (received for review November 12, 2011). Published ahead of print February 27, 2012. We thank Mr. Katsuyuki Tanimoto and Mr. Takahiro Shiraishi for their assistance in performing the PET experiments. We also thank Ms. Yoshiko Fukushima for her help as clinical research coordinator. A part of this study is the result of “Integrated research on neuropsychiatric disorders” carried out under the Strategic Research Program for Brain Sciences by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT). This work was supported by a Grant-in-Aid for Scientific Research in Innovative Areas: Prediction and Decision Making (23120009); a Grant-in-Aid for Young Scientist A (23680045); a research grant from the Takeda Science Foundation; a research grant from the Casio Science Foundation; and a consignment expense for Molecular Imaging Program on “Research Base for PET Diagnosis” from MEXT. Author contributions: H. Takahashi, H. Takano, and C.F.C. designed research; H. Takahashi, H. Takano, T.I., R.A., F.K., M.Y., Y.E., and H.I. performed research; H. Takahashi and H. Takano contributed new reagents/analytic tools; H. Takahashi, H. Takano, S.O., H.M., Y.T., and K.T. analyzed data; and H. Takahashi, H. Takano, C.F.C., T.M., Y.O., M.K., and T.S. wrote the paper.
Funding AgencyGrant Number
Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of JapanUNSPECIFIED
Japan Society for the Promotion of Science (JSPS)23120009
Japan Society for the Promotion of Science (JSPS)23680045
Takeda Science FoundationUNSPECIFIED
Casio Science FoundationUNSPECIFIED
Subject Keywords:positron emission tomography; decision-making; fairness
Issue or Number:11
PubMed Central ID:PMC3306703
Record Number:CaltechAUTHORS:20120404-084337453
Persistent URL:
Official Citation:Hidehiko Takahashi, Harumasa Takano, Colin F. Camerer, Takashi Ideno, Shigetaka Okubo, Hiroshi Matsui, Yuki Tamari, Kazuhisa Takemura, Ryosuke Arakawa, Fumitoshi Kodaka, Makiko Yamada, Yoko Eguchi, Toshiya Murai, Yoshiro Okubo, Motoichiro Kato, Hiroshi Ito, and Tetsuya Suhara Honesty mediates the relationship between serotonin and reaction to unfairness PNAS 2012 109 (11) 4281-4284; published ahead of print February 27, 2012, doi:10.1073/pnas.1118687109
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29970
Deposited By: Ruth Sustaita
Deposited On:04 Apr 2012 16:32
Last Modified:09 Nov 2021 19:33

Repository Staff Only: item control page