28 juin 2012 – Interdisciplinary Workshop on Collective Decision

Télécharger le programme détaillé de ce workshop du 28 juin 2012



Cendri Hutcherson

(California Institute of Technology-CALTECH) : Distinctive Motive For Altruism

We use human neuroimaging to identify two qualitatively different motivations underlying the willingness to sacrifice one’s own resources for others’ benefit. First, we find that brain regions involved in self-control implement norm-based motives for sacrificing (i.e. « do the right thing »). In contrast, regions involved in social cognition and valuation implement welfare-based motives for sacrificing (i.e. « caring about others »). Using these regions as neural markers, we also find that norm-based motives tend to be used only when welfare-based motives are weak, and are associated with less giving in an anonymous context.


Alan Kirman

(Groupement de Recherche en Economie Quantitative d’Aix-Marseille-GREQUAM) : Collective Economic Decisions : Some Lessons from Entomology

I will first discuss the difficulties that result from assuming, as is done in macroeconomics, that aggregate decisions can be assimilated to those of a single « rational » individual. This is particularly important at the current time when contagion, panic and the breakdown of networks have contributed in large measure to the emergence of the crisis. We need models which analyse the emergence of collective behaviour from the decisions of interacting individuals. In the second part I will examine some examples of the collective behaviour of ants bees and spiders and suggest how we might learn something from them about human collective behaviour.


Ian Krajbich

(University of Zurich) : Neurometrically Informed Mechanism Design

It is well known that private information can cause huge inefficiencies in many different economic domains including public goods, bargaining, and consumer purchasing. Here I show, both theoretically and experimentally, that by measuring neural signals that are informative of private information, we can achieve full efficiency and overcome classic impossibility results in the literature.


James Marshall

(University of Sheffield) : Optimality theory and voting processes

Political theory suggests that optimal voting systems are impossible. Recent years, however, have also seen growing interest in applying aspects of political theory to ’optimal’ collective animal behaviour. I will give an overview of some of the theory, reviewing what is applicable and what is not. The examples I will use are primarily from neuroscience and social insect collective behaviour. These illustrate how looking at apparently different systems using the same tools can highlight interesting similarities, as well as differences, and suggest new research directions.


Jean-Pierre Nadal

(Ecole normale supérieure-ENS) : Cycles of cooperation and free-riding in social systems work with Yiping P. Ma, Sebastian Gonçalves, Sylvain Mignot and Mirta B. Gordon

Basic evidences on non-profit making and other forms of benevolent-based organizations reveal a rough partition of members between some ’pure consumers’ of the public good (free-riders) and ’benevolent’ individuals (cooperators). We study the relationship between the community size and the level of cooperation in a simple model where the utility of joining the community is proportional to its size. We show that the system presents two types of equilibria : fixed points (Nash equilibria) with a mixture of cooperators and free-riders, and cycles where the size of the community, as well as the proportion of cooperators and free-riders, varies periodically.


Mathias Pessiglione

(Institut du Cerveau et de la Moelle Epinière) : Mechanisms of desire contagion across human brains (doc1 – doc2)

Cerebral mechanisms of mimetic desire lead to a contagion of preferences.


Stephen Pratt

(Arizona State University) : Psychology of a superorganism : Collective decision-making by ant colonies

Insect societies are leading examples of collective cognition by animal groups. Much like a single animal, a colony as a whole can evaluate its surroundings, process information, and make decisions. This cognition emerges from interactions among the colony’s members, just as individual cognition emerges from interactions among neurons in the brain. In this talk I will describe how ant colonies make a collective comparison of potential new homes even when no individual ant directly assesses all of the candidates. I will then show how this constraint on individual performance paradoxically helps the group, by preventing certain kinds of errors that would otherwise result from the cognitive limitations of single ants.


Robert Sugden

(University of East Anglia) : Neither self-interest nor self-sacrifice : the fraternal morality of market relationships

Current theories of social preferences treat trust and reciprocity as interactions between individuals with self-sacrificing motivations to reward ‘kindness’ and punish ‘unkindness’. Many forms of trust are better understood as cooperation for mutual benefit, as represented by theories of team reasoning. Applied to market relationships in general, the team-reasoning approach leads to an understanding of such relationships as having moral content without involving self-sacrifice.