Submitted on December 3, 2007
Accepted on April 21, 2008
The Right and the Good: Distributive Justice and Neural Encoding of Equity and Efficiency
Ming Hsu 1
, Cédric Anen 2, Steven R. Quartz 2*
1 Beckman Institute for Advanced Science and Technology, and Department of Economics, University of Illinois at Urbana-Champaign
2 Social Cognitive Neuroscience Laboratory, Division of Humanities and Social Sciences 228-77, California Institute of Technology, Pasadena, CA 91125, USA.
* To whom correspondence should be addressed.
Steven R. Quartz , E-mail: steve{at}hss.caltech.edu
These authors contributed equally to this work.
Distributive justice concerns how individuals and societies distribute benefits and burdens in a just or moral manner. Combining distribution choices with functional magnetic resonance imaging (fMRI), we investigate the central problem of distributive justice: the tradeoff between equity and efficiency. We find that the putamen responds to efficiency, whereas the insula encodes inequity, and the caudate/septal subgenual region encodes a unified measure of efficiency and inequity (utility). Strikingly, individual differences in inequity aversion correlate with activity in inequity and utility regions. Against utilitarianism, our results support the deontological intuition that a sense of fairness is fundamental to distributive justice, but, as suggested by moral sentimentalists, is rooted in emotional processing. More generally, emotional responses related to norm violations may underlie individual differences in equity considerations and adherence to ethical rules.
