We are investigating an attraction mechanism that models interpersonal relations such that an individual acts differently, and presumably more cooperatively, with those to whom it is attracted than with others. This is a generic mechanism and the types of relations envisaged can range from regular physical attraction to attachment of toddlers to caregivers. We have shown in the past that the introduction of this attraction mechanism in an iterated prisoner's dilemma game yields higher average agent scores in tournaments within uniform or mixed populations. In the present work, we show that this mechanism has an evolutionary advantage and that it can evolve in various ways (probability of attraction, network of attraction). These results show that cooperation and social stability can be enhanced by psychological mechanisms that are external to the game setting but interfere with it and that these mechanisms may be further selected and reinforced by evolution and catalyze cooperation. We further show that evolution of attraction in the context of cooperation is possible in fairly small networks of homogeneous agents with noise but not in networks of heterogeneous agents without noise. This remark has interesting implications for the study of the origins of human cognition.

In this work, we are studying the dynamics of wealth inequality in a simulated primitive economy of producer agents. These agents represent families that live, produce and move in an environment that can be unstable. The families have different technological abilities and can decide differently about sharing produced food with others – i.e., whether to share through public stores and how much – or keeping it all for themselves and become wealthier. We show through agent-based modelling that in a competitive environment with cultural evolution, where agents that survive pass their behavioral profiles to their descendants, wealth inequality between agents follows an initially upward and then downward trend before stabilizing around its final value. This trend is reminiscent of swings identified by economists. We study it in cases of “shocks”, where after stabilization one of the parameters of the system is reinitialized (technology, environment, birth model and others). In all cases, the after-shock inequality movement shows the same overall trend but it is smaller in size, and this is true irrespective of the sharing outcome. We formulate the hypothesis that the size of the emerging maximum inequality is due to cultural reinitialization or innovation, where because of the shock the agents reinitialize their stances toward sharing, i.e. they innovate culturally. This hypothesis is supported by a series of experiments with varying degrees of cultural innovation as well as by an experiment with generalized cultural evolution. The global conclusion is that it is the cognitive/cultural lever of the economic relations, here the disposition toward sharing, that is responsible for the type and breadth of inequality that emerges.

We are studying food sharing and the conditions of its evolution in sedentary, agricultural societies. We start from the conjecture that when food, and by extension any type of wealth, can be stored for public use in greater quantities than what can be stored for private use, then sharing evolves, otherwise it does not. We present a simulated environment where agents represent families that produce, consume and store food in private or in public stores. The relative capacities of the private and public stores are responsible for the evolution or not of generalized sharing in the population. Although storage capacity is represented in the model as a technological parameter, it is not purely technological, but it is also the result of social and cultural choices and it goes hand in hand with communal or individualist behavioral profiles and stances. We show that when the public sphere is given a culturally greater value than the private sphere and therefore public storage capacity is higher than private capacity, then sharing emerges. This is more pronounced in risky and unstable environments. Inversely, if private capacity rises to very high levels compared to the public one, sharing collapses. Similar results are obtained even when other processes are present, such as costly sharing and theft. Our conclusion is therefore that sharing can emerge in a sedentary population when storage is possible and it will be maintained as long as individuals can store only limited amounts of food or other wealth. We delineate the implications of our study for further research on sharing and inequality.

We are presenting a study on mood that purports to contribute to an understanding of its evolution as a personal strategy and as a prosocial automatic contagion-based mechanism that both improve decision making. We present an environment where an agent interacts with objects of varying difficulty and where its mood is both a dispositional factor that influences its decision making and an information variable that aligns with the history of its interactions. We show that for very competent and very incompetent agents the mood has a positive effect on their obtained performance and that on average for the whole population the mood mechanism would be selected by evolution. We also examine a mechanism of automatic mood contagion that favors all but the most incompetent agents and on average the whole population and we show that contagion would again be selected by evolution. We delineate the implications of our model for further research on moods.

Imitation is ubiquitous: human adults imitate, human infants, preschoolers, and adolescents all imitate, some animals too imitate. Moreover, imitation may be automatic, spontaneous, or deliberate and humans may specifically select their imitation models as well as the imitated target feature or object. Finally, language, gestures, motor patterns, and high-level behaviors can all be imitated at varying degrees of detail and in a variety of modulating contexts. These are some major aspects of the study of the broad class of cognitive processes called imitation, whether and how it has evolved and its relation to empathy, mind-reading, language, culture, and social learning in general (Hurley and Chater, 2005; Heyes et al., 2009; Jones, 2009, Shea, 2009; Claidière and Sperber, 2010; Gerrans, 2013; Hodges, 2014). Because of this ubiquity, imitation is sometimes used with diversified or more restricted meanings, such as mimicry and emulation (van Baaren et al., 2009; Whiten et al., 2009), and research efforts often center on the neural and behavioral organization that allows imitation to happen (Brass and Heyes, 2005). We are focusing on the relation of imitation with association, as a basic mechanism of behavioral emergence, and with communication, as the general function of imitation (communication need not be thought as purely linguistic, though1). Our goal is to discuss the nexus of the three concepts (imitation, association, communicative function) and to propose a plausible view of the initial steps taken by evolution in the development of general social and communicative behavior. Thus, we propose an incremental process of generative and selective imitation starting from proto-imitation that replicates external signals without associating with target objects or functionality, and proceeding to proto-association that relates to higher-order imitation and attributes “meaning” or function to external signals. We are therefore discussing a model that allows proto-imitation outside explicit communication but may allow emergence of communication in the medium or long term ontogenetically. The idea is to separate response imitation from response association to external meaning so as to make room both for species that can imitate but not associate meaning and for disabled humans that cannot associate well or even proto-imitate well. Thus, we regard and model association as a generic functional concept, initially Hebbian at the neural level (“what fires together, wires together”), but more intricate at higher levels (Cooper et al., 2013). In what follows, we present in order the proto-imitation concept and model, the predictions about its function in regular configurations or in cognitively extreme cases, the basic meaning association model and, lastly, further behavioral high-level predictions at organism level. We have verified computationally some of the predictions elsewhere and all of them match actual evidence obtained experimentally. We conclude with further thoughts about the proposed model.

We experiment with a linguistic change mechanism in a community of interacting agents and show the various phenomena that may emerge under different social constraints. We assume phonological and lexical learning and a semantic reference to external objects in the environment. Distinct groups of agents with initially different languages converge to a common language, with the relevant frequency of inter-agent interactions controlling which language dominates. Moreover, an initially monolingual community diverges due to social factors creating agent grouping, where agents interact more frequently with members of the same group. Additional cognitive features, like innovation and attention , lead to increased linguistic divergence between groups and word bistability. Finally, cultural learning leads to continuous linguistic change and occasional coexistence of multiple words, as well as revival of rare words. Overall, it appears that the initial community may evolve in arbitrary directions, and languages may dynamically form, split , mutate, and oscillate.

We study a simple social competition mechanism and the effect of various cognitive variants on the emerging stratification structure. We depart from a basic mammal-inspired competition mechanism relying solely on physical strength and introduce a number of higher level cognitive parameters, especially individual imposition and submission factors that modulate the agents’ decision to fight . The emerging structure is generally a society spread out in status range, without any obvious polarization. Next, the concept of a “stratification game” is introduced, where some fights are spontaneously resolved if differences between agents are mutually perceived as too large. Some game variants lead to fairly egalitarian societies, while others, based on withdrawal from fights , lead to extremely unequal societies. This property also holds in realistic competition environments involving resource sharing and task competition . Overall, our study shows how certain socio-cultural conventions may overtake cognitive factors and define the emerging social stratification outcome.

In this work, we are presenting a simple model of combined linguistic change at the phonological and at the lexical level. We experiment with the model by using agent-based simulation: two groups of agents that speak initially different languages interact through participation in different social activities. It is shown that the lexicon size initially grows and later shrinks as the agents converge to a monolingual configuration. The final language that emerges is determined by the relative percentage of the two populations initially, since this percentage defines the average frequency of interactions. Thus always the dominant language is the one of the majority, in the sense that the words of the final language are closer to or even copied from the language of the majority. Variations in the structure of interaction between the two groups will lead to a linguistic mix. The addition of a new parameter, called intensity of interaction, and expressing differential attention to different speakers, may revert these tendencies and yield languages where the language of a minority may finally dominate, such as in a realistic master-slave scenario where the dominant language is the master’s language independently of relative size of the two populations.

This short article presents a discussion of the relevance of mind reading tests to general testing of intelligence and an example of mind-reader behaviours for the IPD. It is discussed how a mind reading capacity may allow intricate emotional behaviours to emerge and how these relate to a broader developmental context.

In this work, we are exploring mechanisms that may contribute to cultural diversity and that rely on our everyday understanding of culture as a set of attitudes, behaviors, tools, ways of thinking etc., some of which are not directly exposed to the outside. We are using as a starting point an extended Axelrod model that defines a Moore neighborhood and generally heterogeneous sets of cultural features per agent. We briefly present next a number of psychologically realistic, basic and more advanced, conceptual models of selfish cultural affinity perception and imitation that have been shown to make the population stabilize to multi-cultural configurations. The shared individualistic, “selfish” nature of these models leads to the definition of another model explicitly representing non-exposed or hidden features that control regular, exposed features. We show that this meta model induces diversity even in the absence of individualistic behaviors and that an adaptation mechanism capable of slowly imitating control features would drive the system close to its theoretical limits. We also show that in some cases the control features’ adaptation process presents punctuated equilibria. Finally, preliminary experiments with various social configurations have shown that the qualitative cultural characteristics of final populations after stabilization depend solely on the original cultures and not on the type of spatial interaction and contact. Thus in some cases initial cultural divides may persist. In sum, our results show that the presence of meta-processes, and especially of control features that are not exposed to the outside but that moderate other regular features, most often leads to stable multicultural but not polarized populations.

This paper presents an imitation mechanism and a study of its behavior in spatial grid-based configurations. The imitation mechanism replicates external signals without associating with objects, as in higher-level imitation; it is therefore a model of proto-imitation where agents imitate unconditionally the agents they happen to interact with. We study the mechanism in 2D space to understand how it influences the emerging spatial structures. Our results indicate that in the absence of "adults", i.e agents that act as tutors and do not imitate others, the whole grid eventually stabilizes to one common language for all agents. This is more rapid when various agent mobility schemes are introduced. Complex local micro-languages may emerge permanently, for example if a fair number of adults is present or temporarily if new words have to be invented from time to time, for example to account for new environmental stimuli or cultural factors. All our results suggest that a purely reactive proto-imitation mechanism can suffice to produce various language configurations in space, without the need for agents to reason explicitly on conditions and possible outcomes of language adoption.

We are studying the well known problem of the sliding puzzle or Npuzzle and we are modeling a number of consecutive extensions and their solution based on the known algorithmic solution. The usual approach to date has been to find optimal solutions (move sequences) to the N-puzzle with the aid of sophisticated special-purpose search methods. Our goal is to study it from a bottom up perspective and to do cognitive modeling of the scalable algorithmic solution that finds suboptimal move sequences but that can do so consistently for a large number of extensions with practically no increase in polynomial complexity. This approach claims both to model for fundamental cognitive skills that are exerted on top of existing intelligent problem-solving methods as well as to identify modules of reasoning that should be included in any scalably intelligent system.

In this paper we present a model of generative proto-imitation that replicates external signals without associating with objects, as in higher-level imitation. A mixed population of adults, that have fixed associations objects-signals, and infants, that do not have associations but imitate unconditionally, endowed with a kinship and interaction structure, allows infants to develop signal affinity with their kin in a variety of conditions and within an initial random world, i.e. in a Babel. Our results indicate that the communicative value of imitation can be discovered after the basic apparatus is in place, rather than that communication is the end to which imitation is the means.

In this paper we study the effect of a reactive attraction mechanism in a population of agents that can develop partner preferences. We use as base task for agent pair interaction the benchmark IPD game in its noisy version. Attraction makes an agent unconditionally cooperative toward an attractive opponent, hence introducing a parallel relation between agents, independent from the social interaction context itself, i.e. from the game. Partner selection can exploit such a given psychological condition and discover attracted partners, despite the fact that attraction itself is nowhere represented in the agent reasoning mechanism but is modeled as an uncontrollable process. The mechanics of partner selection are studied systematically in simulation.

Information Sciences 2007, pp. 411-417 (2007) No AccessATTRACTION AND COOPERATION IN NOISY ENVIRONMENTSELPIDA TZAFESTASELPIDA TZAFESTASInstitute of Communication and Computer Systems, National Technical University of Athens Zographou Campus, Athens, 15773, Greecehttps://doi.org/10.1142/9789812709677_0058Cited by:2 (Source: Crossref) PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: This paper presents an attraction mechanism and a study of its behavior in noisy IPD games. The attraction mechanism is coupled with a regular IPD strategy to produce the final agent's behavior. More specifically, an agent follows its regular strategy unless it faces an attractive agent. In the latter case, she becomes unconditionally cooperative. This mechanism is shown to yield higher average agent scores in agent tournaments than if it were not present. Benefits are higher for higher attraction factors, bigger populations or populations of "irrational" agents (that do not retaliate or reason, such as ALLD). We have also studied the impact of the attraction pairing type (whether reciprocal or not) and we have found that random not necessarily reciprocal pairing is the best, because even in the absence of reciprocity a rational agent can cooperate consistently with a cooperating attracted, even if irrational, opponent. We have also experimented with groups of agents that can only be attracted between them. All our results suggest that psychological mechanisms external to the economic setting can interfere with it and can actually lead to enhanced cooperation and social stability despite environmental noise and agent irrationality. FiguresReferencesRelatedDetailsCited By 2Cited by lists all citing articles based on Crossref citation.Constraints and effects of partner selection on the emergence of structures in social environmentsElpida S. Tzafestas1 Dec 2011Cultural diversity dynamicsElpida S. Tzafestas1 Apr 2011 Recommended Information Sciences 2007Metrics History PDF download

This paper presents an attraction mechanism and a study of its behavior in noisy spatial IPD games. The attraction mechanism is coupled with a regular IPD strategy to produce the final agent's behavior. We study the mechanism in 2D space to understand how it influences the emerging spatial structures. We find that any agent strategy, even a plainly irrational one, may become stable in a spatial game given appropriate attraction relations with the neighbors. Also, often the removal of attraction after stabilization causes no qualitative effect. Then we study the effect of introduction of "extreme" agents, such as a "Don Juan" agent that is attracted by all others. Such agents can change dramatically the structure of emerging spatial strategy blocks. Especially the addition or removal of agents after stabilization almost always leads to re-organization and re-stabilization to a new configuration. Various parameters of this model are studied and finally the notion of mobility in relation to evolution is rediscussed. All our results suggest that psychological mechanisms external to the actual "problem" (here IPD) can interfere with it and can actually lead to enhanced cooperation and social stability despite environmental noise and agent irrationality. Moreover, all social/spatial variants that induce more interactions between agents with non-reciprocal attraction relations (such as the extreme agents), are bound to lead to a better social average and to more complex structures.

In this paper we study the evolutionary potential of a reactive attraction mechanism in a population of agents that interact via cooperation games, as exemplified by the noisy iterated prisoner’s dilemma. Attraction makes an agent unconditionally cooperative toward an attractive opponent, hence introducing a parallel relation between agents, independent from the social interaction context itself, i.e. from the game. An additional partner selection mechanism can exploit such a given psychological condition and discover attracted partners, despite the fact that attraction itself is nowhere represented in the agent reasoning mechanism but is modeled as an uncontrollable process. We show how evolution can select attraction at various levels of increasing complexity and how each level triggers the selection of the next one, provided the corresponding mechanisms emerge behaviorally. We also discuss the implications of these experiments for the study of the evolution of complex cognitive capacities and functionalities.