The September 11 attack on the US has revealed an unprecedented terrorism with worldwide range of destruction. It is argued to result from the first worldwide percolation of passive supporters. They are people sympathetic to the terrorism cause but without being involved with it. They just do...

The combined effects of collective beliefs and individual inflexibility in the dynamics of a public debate are investigated using the Galam sequential probabilistic model of opinion dynamics. The study is focused on pair interactions for which the bias produced by collective beliefs is the...

A model for the dynamics of opinion forming in democratic public debate is presented. Using concepts and techniques from the physics of disorder the dynamics of social refusal spreading is studied within a perfect world, where the minority holds neither better arguments nor lobbying backing. The...

The effect of majority rule voting in hierarchical structures is studied using the basic concepts from real space renormalization group. It shows in particular that a huge majority can be self-eliminated while climbing up the hierarchy levels. This majority democratic self-elimination...

We discuss a cellular automata model to study the competition between an emergent better fitted species against an existing majority species. The model implements local fights among small group of individuals and a synchronous random walk on a 2D lattice. The faith of the system, i.e., the...

The recent astonishing wide adhesion of French people to the rumor claiming ‘No plane did crash on the Pentagon on September 11’, is given a generic explanation in terms of a model of minority opinion spreading. Using a majority rule reaction–diffusion dynamics, a rumor is shown to invade...

The dynamics of wine purchasing behavior is studied focusing on the respective impacts of the word-to-mouth versus wine expert judgements and reputations. To investigate the problem we apply the Galam model of opinion dynamics to agents who have to select a preference about which type of wine to...

The work aims to investigate a paradigm of instability in coalition forming among countries, using a model inspired from Statistical Physics. The instability is a consequence of decentralized maximization of the individual benefits where contradictory associations into coalitions occur due to...

The concept and technics of real space renormalization group are applied to study majority rule voting in hierarchical structures. It is found that democratic voting can lead to totalitarianism by keeping in power a small minority. Conditions of this paradox are analyzed and singled out. Indeed...