270 research outputs found
Evolution of cooperation driven by zealots
Recent experimental results with humans involved in social dilemma games
suggest that cooperation may be a contagious phenomenon and that the selection
pressure operating on evolutionary dynamics (i.e., mimicry) is relatively weak.
I propose an evolutionary dynamics model that links these experimental findings
and evolution of cooperation. By assuming a small fraction of (imperfect)
zealous cooperators, I show that a large fraction of cooperation emerges in
evolutionary dynamics of social dilemma games. Even if defection is more
lucrative than cooperation for most individuals, they often mimic cooperation
of fellows unless the selection pressure is very strong. Then, zealous
cooperators can transform the population to be even fully cooperative under
standard evolutionary dynamics.Comment: 5 figure
Zealots in the mean-field noisy voter model
The influence of zealots on the noisy voter model is studied theoretically
and numerically at the mean-field level. The noisy voter model is a
modification of the voter model that includes a second mechanism for
transitions between states: apart from the original herding processes, voters
may change their states because of an intrinsic, noisy in origin source. By
increasing the importance of the noise with respect to the herding, the system
exhibits a finite-size phase transition from a quasi-consensus state, where
most of the voters share the same opinion, to a one with coexistence. Upon
introducing some zealots, or voters with fixed opinion, the latter scenario may
change significantly. We unveil the new situations by carrying out a systematic
numerical and analytical study of a fully connected network for voters, but
allowing different voters to be directly influenced by different zealots. We
show that this general system is equivalent to a system of voters without
zealots, but with heterogeneous values of their parameters characterizing
herding and noisy dynamics. We find excellent agreement between our analytical
and numerical results. Noise and herding/zealotry acting together in the voter
model yields not a trivial mixture of the scenarios with the two mechanisms
acting alone: it represents a situation where the global-local (noise-herding)
competitions is coupled to a symmetry breaking (zealots). In general, the
zealotry enhances the effective noise of the system, which may destroy the
original quasi--consensus state, and can introduce a bias towards the opinion
of the majority of zealots, hence breaking the symmetry of the system and
giving rise to new phases ...Comment: 13 pages, 15 figure
Influence of opinion dynamics on the evolution of games
Under certain circumstances such as lack of information or bounded
rationality, human players can take decisions on which strategy to choose in a
game on the basis of simple opinions. These opinions can be modified after each
round by observing own or others payoff results but can be also modified after
interchanging impressions with other players. In this way, the update of the
strategies can become a question that goes beyond simple evolutionary rules
based on fitness and become a social issue. In this work, we explore this
scenario by coupling a game with an opinion dynamics model. The opinion is
represented by a continuous variable that corresponds to the certainty of the
agents respect to which strategy is best. The opinions transform into actions
by making the selection of an strategy a stochastic event with a probability
regulated by the opinion. A certain regard for the previous round payoff is
included but the main update rules of the opinion are given by a model inspired
in social interchanges. We find that the dynamics fixed points of the coupled
model is different from those of the evolutionary game or the opinion models
alone. Furthermore, new features emerge such as the resilience of the fraction
of cooperators to the topology of the social interaction network or to the
presence of a small fraction of extremist players.Comment: 7 pages, 5 figure
Commitment versus persuasion in the three-party constrained voter model
In the framework of the three-party constrained voter model, where voters of
two radical parties (A and B) interact with "centrists" (C and Cz), we study
the competition between a persuasive majority and a committed minority. In this
model, A's and B's are incompatible voters that can convince centrists or be
swayed by them. Here, radical voters are more persuasive than centrists, whose
sub-population consists of susceptible agents C and a fraction zeta of centrist
zealots Cz. Whereas C's may adopt the opinions A and B with respective rates
1+delta_A and 1+delta_B (with delta_A>=delta_B>0), Cz's are committed
individuals that always remain centrists. Furthermore, A and B voters can
become (susceptible) centrists C with a rate 1. The resulting competition
between commitment and persuasion is studied in the mean field limit and for a
finite population on a complete graph. At mean field level, there is a
continuous transition from a coexistence phase when
zeta=
Delta_c. In a finite population of size N, demographic fluctuations lead to
centrism consensus and the dynamics is characterized by the mean consensus time
tau. Because of the competition between commitment and persuasion, here
consensus is reached much slower (zeta=Delta_c) than
in the absence of zealots (when tau\simN). In fact, when zeta<Delta_c and there
is an initial minority of centrists, the mean consensus time asymptotically
grows as tau\simN^{-1/2} e^{N gamma}, where gamma is determined. The dynamics
is thus characterized by a metastable state where the most persuasive voters
and centrists coexist when delta_A>delta_B, whereas all species coexist when
delta_A=delta_B. When zeta>=Delta_c and the initial density of centrists is
low, one finds tau\simln N (when N>>1). Our analytical findings are
corroborated by stochastic simulations.Comment: 25 pages, 6 figures. Final version for the Journal of Statistical
Physics (special issue on the "applications of statistical mechanics to
social phenomena"
How Committed Individuals Shape Social Dynamics: A Survey on Coordination Games and Social Dilemma Games
Committed individuals, who features steadfast dedication to advocating strong
beliefs, values, and preferences, have garnered much attention across
statistical physics, social science, and computer science. This survey delves
into the profound impact of committed individuals on social dynamics that
emerge from coordination games and social dilemma games. Through separate
examinations of their influence on coordination, including social conventions
and color coordination games, and social dilemma games, including one-shot
settings, repeated settings, and vaccination games, this survey reveals the
significant role committed individuals play in shaping social dynamics. Their
contributions range from accelerating or overturning social conventions to
addressing cooperation dilemmas and expediting solutions for color coordination
and vaccination issues. Furthermore, the survey outlines three promising
directions for future research: conducting human behavior experiments for
empirical validation, leveraging advanced large language models as proxies for
committed individuals in complex scenarios, and addressing potential negative
impacts of committed individuals
- âŚ