Research On The Dynamics Of Cooperative Behavior And Collective Behavior Based On Spatial Network

Cooperative behavior is widespread in nature and human society,but according to the theory of Darwin's natural selection individuals tend to maximize their own interests,the cooperators will disappear.Apparently,it can't explain the reason for the widespread cooperative behavior,so to explain the appearance of cooperative behavior and the evolution of cooperation system have been one of the important issues that biologists,behavioral economists and statisticians try to solve.The study of game theory and evolutionary game theory provide effective theory and framework to explain the appearance and maintaining of cooperation.Network can effectively portray the relationship between individuals in population.In recent years,the combination of spacial network and game theory has caused many home and abroad scholars' attention.The basic model of game theory mainly includes the prisoner's dilemma,snowdrift game,public goods game and “rockscissor-paper” model,to name but a few.Basic network mainly including twodimensional grid,small-world networks,random networks and scale-free networks.In this paper,we mainly talk about square lattice network.Behavioral economics in this paper is organized to study the cooperative behavior between different individuals.Besides,this paper considers that initial wealth of each people may has difference in the real world,and in order to study the effect of initial wealth,we organize collective risk climate change game experiment.Experiment is divided into initial wealth homogeneous groups and heterogeneous groups,including homogeneous group(C1)which has 64 participants,and divided into eight groups.There exists three groups achieve the goal after 10 rounds investment,success rate is 37.5%;Heterogeneous group divides into the group T1,T2 and T3,success rates are 90%,70% and 80% respectively.We can summarize from the experiment results that heterogeneous distribution can promote collective contribution behavior to reach the goal compared with homogeneous distribution.Then,we establish a generalized linear model to study the factors which influence individual investment behavior.We find that science major,higher initial wealth and heterogeneous distribution can promote individual's investment behavior.Finally,we analyze the experimental data and establish hierarchical clustering model to classify the behavior of the individual.Homogeneous and heterogeneous group both can be divided into three categories: freerider,cooperator and super cooperator.Free-riders' investment is far less than 1 in each round,cooperators' investment is fluctuate near 1 in each round,super cooperators' investment is far more than 1 in each round.The following two studies mainly based on the prisoner's dilemma and we proceed numerical simulations on the space network.In the fourth chapter,we explore how the coevolution of link weights and strategies affect the density of cooperation.Simulation results conclude that with the increase of the link weights,the heterogeneity of network increase as well,thus promotes the evolution of cooperation.Furthermore,we also study the influence of individuals' reputation,and find that considering reputation can increase the number of cooperators.In addition,in the fifth chapter we study the influence of environmental factor based on the three strategies in the prisoner's dilemma model.Through numerical simulation,we find that it can promote the evolution of cooperation with the increase of environmental factor.At the same time,with the increase of the temptation to defect,it will reduce the influence of the environment factor,and the entire population will reach a state of coexistence of three strategies.