@inproceedings { anh13, booktitle = {in Proc. of 23rd International Joint Conference on Artificial Intelligence (IJCAI 2013), AAAI Press}, keywords = {Game Theory;Multi-Agent Societies;Miscellaneous;}, title = {Why is it so hard to say sorry? Evolution of Apology with Commitment in the Iterated Prisoner’s Dilemma}, volume = {in press}, year = {2013}, author = {Han The Anh and Luis Moniz Pereira and Francisco C. Santos and Tom Lenaerts} }