Nectunt Blog

Social Dilemmas and Human Behavior


Cooperation and corruption

(Versión en español aquí)

In this post I am going to briefly summarize a study recently published in PNAS by Ori Weisel and Shaul Shalvi entitled “The collaborative roots of corruption“. Cooperation has indisputable beneficial effects, but in this particular case the researchers were interested in its negative effects, and to that end they designed the following game: two people, A and B, in complete isolation and alone, have to throw a die. The subsequent procedure and payments are as follows: Continue reading


Yes, the driver of cooperation in dynamic networks is nothing but reputation

(Versión en español aquí)

In the very first post of this blog, I already introduced the idea of dynamic networks as a way out of the lack of experimental evidence on the promotion of cooperation by the structuring of the interactions (although recently an experiment has shown that there might be some such promotion when the temptation to defect is small, you should expect a post about this at some point soon). Recently, we set out to check exactly how this worked by looking at the effect of reputation, i.e., of the information given to experimental subjects about previous actions of their possible partners. This is described in our website Nectunt, under “Dynamic Networks and Reputation”, and has appeared a few weeks ago as Reputation drives cooperative behaviour and network formation in human groups, by José A. Cuesta, Carlos Gracia-Lázaro, Alfredo Ferrer, Yamir Moreno and Angel Sánchez, Scientific Reports 5, 7843 (2015). In a nutshell, what we found there is that the possibility to change links, by itself, does not promote cooperation; it has to be combined with information on the past actions of partners in order to induce a more cooperative behavior.

It is therefore very nice to report here a confirmation of this result, that has just appeared: The effects of reputational and social knowledge on cooperation, by Edoardo Gallo and Chang Yan, Proceedings of the National Academy of Sciences of the USA 112, 3647-3652 (2015). We knew about this work prior to publication, thanks to our common friend Antonio Cabrales who learned from Edo what they were doing and put us in contact, and we had a nice exchange of ideas. Later, I was external examiner of Chang’s Ph D Thesis at Oxford, which I enjoyed very much. Thus, it is a pleasure to talk about their work here.

Continue reading


Leave a comment

Rationality and cooperation (I).

In my first entry on this blog, let me address a topic that constitutes a key point in almost any study on human behavior, namely rationality. The word rational belongs to everyday language, and its meaning depends strongly on the context in which it is used. Even in its technical sense, rationality does not have a single meaning, having different meanings in evolutionary biology, sociology, economics and politics. And even within a particular science, rationality may have different forms: the German sociologist Max Weber distinguished four types of rationality. Just as any other sociological approach, this interpretation has its detractors, among them pragmatists. In this entry, I will try to discuss what could be called rational in a certain number of situations modeled by game theory, and not always coincide with the classical definition of rationality as utility maximization.

(Versión en español aquí)
Continue reading