Homo moralis - Preference evolution under incomplete information and assortative matching

Ingela Alger, and Jörgen W. Weibull


What preferences will prevail in a society of rational individuals when preference evolution is driven by the resulting payoffs? We show that when individuals' preferences are their private information, a convex combination of selfishness and morality stands out as evolutionarily stable. We call individuals with such preferences homo moralis. At one end of the spectrum is homo oeconomicus, who acts so as to maximize his or her own payoff. At the opposite end is homo kantiensis, who does what would be “the right thing to do,” in terms of payoffs, if all others would do likewise. We show that the stable degree of morality—the weight placed on the moral goal—is determined by the degree of assortativity in the process whereby individuals are matched to interact.


evolutionary stability; preference evolution; moral values; incomplete information; assortative matching;


Ingela Alger, and Jörgen W. Weibull, Homo Moralis-Preference evolution under incomplete information and assortative matching, TSE Working Paper, n. 12-281, February 2012.

See also

Published in

Econometrica, vol. 81, n. 6, November 2013, pp. 2269–2302