Cooperation、Altruistic、Punishment、Fair distribution、Sending signals...social behaviors such as this are ubiquitous in humans and other social animals，And in the maintenance of its group structure、Plays an important role in development and evolution。Explain the causes of social behavior，Revealing the conditions of its origin and evolution、Mechanism and process，Is an important issue in social science philosophy，It has important theoretical and practical significance for understanding the nature of sociality。Traditional rational choice theory believes that，The emergence of social behavior is the result of human choices based on rational reasoning abilities in the "state of nature"。However，More and more research findings，Traditional rational choice theory is insufficient to explain the origin of social behavior。On the one hand，Many human social behaviors violate some basic principles of rational choice theory；On the other hand，Social behavior is not unique to humans，Some animals that are generally considered to have no or only low rational thinking abilities，Also exhibits social behavior similar to humans。As opposed to，As an interdisciplinary theoretical framework, bet365 cricket odds has flourished in the past 20 years，Provides a new theoretical tool with great potential for studying the origin and evolution of social behavior。

　　bet365 cricket odds and development

The predecessor of bet365 cricket odds is game theory in the field of economics，Originally used to study human economic behavior。After the idea of ​​game theory was introduced into evolutionary biology，After transformation and development by biologists，The theoretical system of bet365 cricket odds has gradually formed。bet365 cricket odds is a successful case of transferring social science theory to biology，The results of its development have recently begun to feed back into research in the field of humanities and social sciences。

In classical bet365 cricket odds，A game usually contains three core elements: players、Strategies and pay-off。These factors can be presented in the form of a pay-off matrix。Take the famous game type “prisoner’s dilemma” in bet365 cricket odds as an example: Suppose two criminal suspects are accused of collaborating to commit a case，and were locked in different rooms for interrogation。These two prisoners become participants in this game (i.e. players)。Each of them has two strategies to choose from: remain silent or betray their accomplices。The key factor that makes this scenario a "game" is that the profit of each player not only depends on the strategy he adopts，Also depends on the opponent’s strategy。When both remain silent，Each was only sentenced to 1 year in prison；When two people betray each other，Both men were sentenced to 5 years in prison；When a person remains silent，When another person betrays the other person，Those who remain silent are sentenced to 10 years，And betrayed his accomplices、The person who provided the information was acquitted。This game can be represented by the payoff matrix shown in the following table。

　The payoff matrix of the "Prisoner's Dilemma" bet365 cricket odds

After game theory was introduced into evolutionary biology，Mainly used to study the evolution of biological phenotypes。Similar to classical game theory，The "game" in bet365 cricket odds also contains three core elements: gamer、Strategy and Benefits。But at the same time，The two theories show significant differences in the following three aspects。

一，In classic games，Gamers are regarded as rational actors，Which strategy a player adopts depends on which strategy can maximize his profits。For example，In the prisoner’s dilemma bet365 cricket odds，Whether the other party chooses to remain silent or betray his accomplices，The profit of an individual who chooses to betray his accomplices is higher than that of remaining silent。Therefore，Out of rational considerations，Every individual will choose to betray their accomplices。But this way，Everyone will be sentenced to five years，It is a worse outcome than both remaining silent - this is why the bet365 cricket odds is called a "dilemma"。And in the evolutionary bet365 cricket odds，Gamers are generally regarded as individuals with no or only low rationality (under certain environmental conditions，The strategy adopted by an individual organism can even be completely determined by its genotype)。

Second，In classic games，A player’s income is generally understood as utility in the economic sense。Utility is often measured by the amount of money，But it can also be measured by other things that players prefer。For example，In Prisoner’s bet365 cricket odds，The change in the length of personal freedom can be used to measure income。And in the evolutionary bet365 cricket odds，Benefit is understood as the change in individual fitness after playing the bet365 cricket odds。In the context of biological evolution，Fitness can be roughly understood as the ability of an organism to survive and reproduce successfully，Usually estimated by the expected number of offspring。

Third，Classical game theory is mainly used to predict or explain the strategic choices of rational actors in game scenarios。The main study of bet365 cricket odds is，How the game between individuals who choose different strategies affects the distribution and evolution of these strategies in the population。

bet365 cricket odds is derived from classical game theory，The scope of its application has subsequently developed from biological evolution to cultural evolution。bet365 cricket odds was originally used to study the evolution of biological traits in nature，These traits are generally thought to be passed between generations through genetic inheritance。However，When the theory is reintroduced into the field of humanities and social sciences，When used to study the evolution of human social behavior，The above assumptions are not completely applicable。Human beings are not only experiencing evolution in the biological sense，Also experiencing evolution in a cultural sense (of course，Cultural evolution is not unique to human society，Like the complex calls of birds during courtship、Social behaviors such as collective hunting of cetaceans，It may also be passed on to future generations through cultural inheritance)。Although the emergence of social behavior requires the existence of certain genes as a basis，But many human social behaviors are not directly inherited through genes，It is learned from others through cultural inheritance such as learning and imitation。Because of this，bet365 cricket odds model for studying social behavior，The modeling method that combines cultural evolution or biological evolution is more commonly used。

It’s worth noting，In cultural evolution，The objects a person learns and imitates are not necessarily his parents bet365 cricket odds biological sense，It can also be your other elders、Friends or even strangers。Learning and imitation strategies are also diverse: a person may choose to imitate the strategies used by those around him who have the highest returns，May imitate the strategies that appear most frequently bet365 cricket odds surrounding area，May also imitate people with specific roles (such as parents、Strategies adopted by teachers or celebrities, etc.。These different learning rules，It will cause cultural evolution to show different dynamic characteristics。

　Applied to bet365 cricket odds research

Study social behavior from the perspective of evolutionary games，The first and most basic work is to construct different types of bet365 cricket odds models，To show how the emergence and maintenance of various social behaviors is evolutionarily possible。In this regard，Some philosophers of science have done a lot of work。The following will take the research on fair distribution and the evolution of language and meaning as examples，Show the methods and achievements of social behavior research from the perspective of bet365 cricket odds。

一，Fair distribution。Some economists have conducted such an experiment: asking two subjects to divide a sum of money，And let each of them write down the percentage they want on a piece of paper in advance。If the sum of the percentages is greater than 1，Then the two of them will get nothing；If the sum of the percentages is less than or equal to 1，Then they can each get the share they want。The research found，Most subjects will choose to ask for 50% or close to 50% share。Then，How to explain bet365 cricket odds phenomenon？

Some bet365 cricket odds researchers have imagined such a scenario: assuming that in a population，Individuals are randomly paired in pairs，Perform the above types of games around one resource。The share requested by each person，can be understood as the strategy adopted by the individual in the game，The average return of each strategy will affect the proportion of that strategy in the next generation of the population。The research found，When the population evolves according to replicator dynamics，In most cases，Individuals who advocate equal distribution will occupy the entire population；But at the same time，There are also situations where many populations eventually evolve into the coexistence of multiple non-even distribution strategies (such as 60% and 40%) (i.e. polymorphic equilibrium)。To solve this problem，Some researchers suggest adding positive correlation to the interaction of strategies，That is, it is not a random pairwise game between individuals，But there is a greater probability of a game between individuals using the same strategy。In this way，The situation where the population evolves into a polymorphic equilibrium has almost disappeared。Some researchers have further spatialized the game between individuals，That is, each individual only plays games with its neighbors，And update your strategy based on the benefits of your neighbors and yourself (such as imitating the strategy adopted by the most successful neighbor)，Similarly, the population can almost always evolve into a state where everyone is equally distributed。Although these models are very ideal，But they provide a new way of thinking about the origin and evolution of fair distribution。

Second，The evolution of language and meaning。An important characteristic of language symbols is their arbitrariness，That is, there is often no necessary connection in terms of natural properties between the phonetic form and meaning of language symbols，It is the result of bet365 cricket odds convention。For example，In Chinese，We use the word "apple" to refer to the fruit apple，But as long as members of the society mutually agree，The word "apple" can also be used to refer to peaches。If language is a communication system based on convention，Then，How those initial linguistic habits were generated and maintained？

The "sender-receiver" signaling bet365 cricket odds proposed by David Lewis in the book "Convention"，Provides an important theoretical framework for studying the above issues。In the "sender-receiver" signaling bet365 cricket odds，The sender can sense what is happening in the world around him and send out some kind of signal，The receiver can respond in some way based on the received signal。If the recipient's response matches the situation，Then both the sender and the receiver can obtain certain benefits；Otherwise，Both returns are zero。

To facilitate discussion，Consider a signaling bet365 cricket odds with only two people。Among them，One person is the sender，Another person is the recipient。Suppose there are only two states of affairsS1, S2}，The sender is only σ1, σ2Two signals can be used，The recipient can only make r1, r2Two reactions，And reaction r1 only matches state of affairs S1，Reaction r2 only matches state of affairs S2。Under this setting，The sender has 4 strategies to choose from。Sender strategy 1: S1→σ1，S2→σ1；Sender strategy 2: S1→σ1，S2→σ2；Sender strategy 3: S1→σ2，S2→σ1；Sender strategy 4: S1→σ2，S2→σ2。The receiver also has four strategies to choose from。Receiver strategy 1:σ1→r1，σ2→r1；Receiver strategy 2:σ1→r1，σ2→r2；Receiver strategy 3: σ1→r2，σ2→r1；Receiver strategy 4: σ1→r2，σ2→r2。Only two combinations of strategies can completely match the reaction to the situation，Thus forming a signaling system。Signal system A:<Sender Policy 2，Receiver Strategy 2；Signal system B:<Sender Policy 3，Receiver Strategy 3。

The above signaling game only occurs between two individuals，And everyone’s role is fixed。The research found，If the framework of signaling games is combined with bet365 cricket odds，Enable individuals in a population to be both senders and receivers，Random pairing between two pairs for signal game，And evolve according to replicator dynamics，Then the population will almost always tend to evolve one of the above two signaling systems。This shows，Under certain conditions，Interacting individuals in a population can spontaneously learn to send signals，And evolve a stable signaling system。

　bet365 cricket odds and Outlook

Although the work on evolutionary game modeling of social behavior has been fruitful，But there are some methodological issues behind this research approach，has not yet been systematically solved and dealt with。This has caused many scholars to question the reliability and validity of social behavior research based on bet365 cricket odds。Only two major criticisms are briefly introduced here。

一，From the explanation of "how is it possible" to the explanation of "how is it actually"。Same as other scientific models，The construction of bet365 cricket odds models must also be based on certain assumptions。When the bet365 cricket odds model is used to explain the origin and evolution of human social behavior，Relevant hypotheses include the structure of early human communities、The mechanism of cultural inheritance、How the game occurs, etc.。Compared to bone structure and other traits，Information related to behavioral traits is extremely difficult to preserve。In most cases，Scientists can only speculate through indirect evidence。Because of this，Some researchers believe，bet365 cricket odds models provide just-so stories。These models do provide some explanation，But it is only a "how-possibly" explanation，That is, under the conditions set by the model，It is possible to generate and maintain certain social behaviors。However，This does not mean that the social behaviors that people have now actually evolved in the ways shown by these models。For example，In the case of fair distribution，Did early human ancestors really play the kind of game described in the model？If the key assumptions in the bet365 cricket odds model cannot be effectively defended and confirmed，Then the explanations they provide are simply explanations of "how it was possible" for social behavior to evolve，Rather than an explanation of “how it actually evolved”。

Second，Explanation of normativeness。As a naturalistic research approach，Social behavior research based on bet365 cricket odds also faces the problem of how to deduce "should" from "is"。Philip Kitcher pointed out，Existing bet365 cricket odds models fail to explain the "superstructure" of concepts and principles by which we evaluate social behavior。For example，In an bet365 cricket odds model about fair distribution，Although the model is set up so that the population almost always evolves into a state where everyone is equally divided，But this does not explain in what sense this allocation is "fair"，Or why you think this distribution method is fair。In addition，When individuals in the model update their allocation strategies，They are based on the income of neighbors and themselves，Rather than whether a certain allocation strategy is fair，This makes the entire model seem irrelevant to fairness。How bet365 cricket odds models can provide insights into the normative character of social behavior, especially moral behavior？This will be an issue that must be considered in the future of social behavior research based on bet365 cricket odds。

If we admit that human society is the product of biological evolution and cultural evolution，Then we have reason to believe，bet365 cricket odds can provide useful insights into the origin and evolution of social behavior。Of course，This does not mean that current bet365 cricket odds can solve all problems，It does not mean that bet365 cricket odds can solve all problems alone in the future。The diversity and complexity of social behavior，Requires us to break through traditional subject boundaries，Achieve different fields (including psychology、Anthropology、Archaeology、Integration of theoretical resources and empirical results from disciplines such as primate research) - bet365 cricket odds has the potential to provide a basic theoretical framework for this synthesis。

　　(Author’s affiliation: School of bet365 cricket odds, Fudan University)