Reciprocal Strategy Research Articles

Cernunnos Interacts with the XRCC4·DNA-ligase IV Complex and Is Homologous to the Yeast Nonhomologous End-joining Factor Nej1

DNA double strand breaks are considered as the most harmful DNA lesions and are repaired by either homologous recombination or nonhomologous end joining (NHEJ). A new NHEJ factor, Cernunnos, has been identified, the defect of which leads to a severe immunodeficiency condition associated with microcephaly and other developmental defects in humans. This presentation is reminiscent to that of DNA-ligase IV deficiency and suggests a possible interplay between Cernunnos and the XRCC4 x DNA-ligase IV complex. We show here that Cernunnos physically interacts with the XRCC4 x DNA-ligase IV complex. Moreover, a combination of sensitive methods of sequence analysis revealed that Cernunnos can be associated with the XRCC4 family of proteins and that it corresponds to the genuine homolog of the yeast Nej1 protein. Altogether these results shed new lights on the last step, the DNA religation, of the NHEJ pathway.

“Better to be safe than to be sorry”: Extinguishing the individual – group discontinuity effect in competition by cautious reciprocation

The individual – group discontinuity effect entails that in mixed-motive situations, such as the Prisoner's Dilemma game (PDG), intergroup interactions are more competitive than inter-individual interactions. Based on Pruitt and Kimmel's (1977) goal/expectation theory and Axelrod's (1984) cooperation theory, we propose a cautious reciprocation model (CRM), which specifies variables that extinguish or reduce the discontinuity effect by enhancing intergroup cooperation. The model entails that, relative to individuals, the cooperative decisions of the more rational and instrumental group members are more strongly determined by a combination of a concern for long-term greed and a fear of anticipated retaliation, leading them to become more responsive to changes in the PDG task and/or social environment, and to follow an instrumental, cautious reciprocation technique. This technique is measured by increases in the level of cooperation (or competition) shown by groups in reaction to changes in the PDG decisions of the other party, or to experimental manipulations in the PDG task environment (i.e., time perspective, reciprocal strategies, reward structure, sequential vs simultaneous play). A summary of the findings of several earlier Utrecht studies and of recent discontinuity research by Insko, Schopler and co-workers yields evidence for the CRM.

Friendship, cliquishness, and the emergence of cooperation

The evolution of cooperation is a central problem in biology and the social sciences. While theoretical work using the iterated prisoner's dilemma (IPD) has shown that cooperation among non-kin can be sustained among reciprocal strategies (i.e. tit-for-tat), these results are sensitive to errors in strategy execution, cyclical invasions by free riders, and the specific ecology of strategies. Moreover, the IPD assumes that a strategy's probability of playing the PD game with other individuals is independent of the decisions made by others. Here, we remove the assumption of independent pairing by studying a more plausible cooperative dilemma in which players can preferentially interact with a limited set of known partners and also deploy longer-term accounting strategies that can counteract the effects of random errors. We show that cooperative strategies readily emerge and persist in a range of noisy environments, with successful cooperative strategies (henceforth, cliquers) maintaining medium-term memories for partners and low thresholds for acceptable cooperation (i.e. forgiveness). The success of these strategies relies on their cliquishness—a propensity to defect with strangers if they already have an adequate number of partners. Notably, this combination of medium-term accounting, forgiveness, and cliquishness fits with empirical studies of friendship and other long-term relationships among humans.

Reactive strategies in indirect reciprocity

Evolution of reactive strategy of indirect reciprocity is discussed, where individuals interact with others through the one-shot Prisoner's Dilemma game, changing their partners in every round. We investigate all of the reactive strategies that are stochastic, including deterministic ones as special cases. First we study adaptive dynamics of reactive strategies by assuming monomorphic population. Results are very similar to the corresponding evolutionary dynamics of direct reciprocity. The discriminating strategy, which prescribes cooperation only with those who cooperated in the previous round, cannot be an outcome of the evolution. Next we examine the case where the population includes a diversity of strategies. We find that only the mean ‘discriminatoriness’ in the population is the parameter that affects the evolutionary dynamics. The discriminating strategy works as a promoter of cooperation there. However, it is again not the end point of the evolution. This is because retaliatory defection, which was prescribed by the discriminating strategy, is regarded as another defection toward the society. These results caution that we have to reconsider the role of retaliatory defection much more carefully.

Environment and Statecraft: The Strategy of Environmental Treaty‐making

1. Introduction 2. The North Pacific Fur Seal Treaty and the Theory of International Cooperation 3. Transnational Cooperation Dilemmas 4. Games with Multiple Equilibria 5. Customary Rights and Responsibilities 6. International Environmental Agreements 7. The Treaty Participation Game 8. The Montreal Protocol 9. Tipping Treaties 10. Compliance and the Strategy of Reciprocity 11. The Depth and Breadth of International Cooperation 12. Trade Leakage and Trade Linkage 13. The Side Payments Game 14. Summary 15. Global Climate Change and the Kyoto Protocol

Emergence of frequency-dependent cooperative strategies in iterated social dilemma: an experimental study

Previous formal work on iterated social dilemma has shown that the strategy prescribing one to cooperate if m or more others cooperated in the previous round and defect otherwise, loses their effectiveness as the group size increases. The only reciprocal strategy formally proved to be effective in an N-person situation is "trigger strategy" (Friedman, 1986). This strategy presumes that people set the threshold for cooperation, m, at its maximum, namely N-1: all members other than self. This study investigated whether people's choice behavior in iterated social dilemma approximated such a strategy. In groups of seven, participants played a social dilemma game repeatedly. They were provided with complete information regarding others' choices in the three preceding rounds, when making a choice in the current round. Results indicated that participants became more reciprocal as the game progressed, responding more sensitively to how many others cooperated in the previous round. Furthermore, the participants used a strategy in the game that were more lenient for reciprocation, with lower threshold for cooperation, than trigger strategy. Implications of current findings and some future directions were discussed.

Competition among cooperators: Altruism and reciprocity

Levine argues that neither self-interest nor altruism explains experimental results in bargaining and public goods games. Subjects' preferences appear also to be sensitive to their opponents' perceived altruism. Sethi and Somanathan provide a general account of reciprocal preferences that survive under evolutionary pressure. Although a wide variety of reciprocal strategies pass this evolutionary test, Sethi and Somanthan conjecture that fewer are likely to survive when reciprocal strategies compete with each other. This paper develops evolutionary agent-based models to test their conjecture in cases where reciprocal preferences can differ in a variety of games. We confirm that reciprocity is necessary but not sufficient for optimal cooperation. We explore the theme of competition among reciprocal cooperators and display three interesting emergent organizations: racing to the "moral high ground," unstable cycles of preference change, and, when we implement reciprocal mechanisms, hierarchies resulting from exploiting fellow cooperators. If reciprocity is a basic mechanism facilitating cooperation, we can expect interaction that evolves around it to be complex, non-optimal, and resistant to change.

Dynamic and kinematic strategies for head movement control.

This paper describes our analysis of the complex head-neck system using a combination of experimental and modeling approaches. Dynamical analysis of head movements and EMG activation elicited by perturbation of trunk position has examined functional contributions of biomechanically and neurally generated forces in lumped systems with greatly simplified kinematics. This has revealed that visual and voluntary control of neck muscles and the dynamic and static vestibulocollic and cervicocollic reflexes preferentially govern head-neck system state in different frequency domains. It also documents redundant control, which allows the system to compensate for lesions and creates a potential for substantial variability within and between subjects. Kinematic studies have indicated the existence of reciprocal and co-contraction strategies for voluntary force generation, of a vestibulocollic strategy for stabilizing the head during body perturbations and of at least two strategies for voluntary head tracking. Each strategy appears to be executed by a specific muscle synergy that is presumably optimized to efficiently meet the demands of the task.

Elements of Reciprocity and Social Value Orientation

This study assessed the impact of social value orientation on the ability of a reciprocal choice strategy to induce high rates of cooperative behavior in a prisoner’s dilemma. Prosocials, competitors, and individualists played against reciprocal strategies for which delay of reciprocation of both cooperation and noncooperation were orthogonally manipulated. As predicted, individualists cooperated most frequently against Tit-for-tat, competitors when retaliation for noncooperation was delayed, and prosocials when their cooperative choice was immediately reciprocated. In addition, it was found that prosocials began “behavioral assimilation” as early as the second of four five-trial blocks and that changes in competitors’ rate of cooperation over time were determined by immediacy of reciprocating cooperation.

Conditional allogrooming in the herb-field mouse

Among members of the family Muridae, the herb-field mouse, Apodemus microps, is unique in that aggression is almost entirely lacking. This species, therefore, is a model organism for experimental studies of social behavior without the confounding influence of aggression. We used video surveillance cameras to assess the importance of self-grooming and allogrooming in the social life of this species. Detailed analysis of individual behavioral sequences using Markov chain methods revealed that self-grooming is a relatively stereotypic, sex-independent activity usually lasting about 8 s. Allogrooming is conditional in the herb-field mouse, because it takes the form of a reciprocal strategy, with the differences between nonmatching bouts varying according to whether the initiator of allogrooming is male or female and whether both interactants are of the same or opposite sex. Our analysis revealed that the exchange of allogrooming bouts between individuals of the same sex is reciprocal, but that males allow females to “defect” more often than vice versa, and males groomed females for longer than predicted by the distribution of individual self-grooming bouts. In those species where the demand for mating by males is far greater than that offered by females, in other words where females may select mates, asymmetry of allogrooming may provide a mechanism for females to test the “suitability” of males for mating. It may also provide the means for males to stimulate females before mating. Furthermore, allogrooming was the only sex-dependent behavior of the several tested in our experiment. As such, we suggest that allogrooming is the predominant premating mechanism in this species.

Do Reciprocal Strategies Work in Social Dilemmas?

According to computer simulations by Parks and Komorita (1997), group-based reciprocal strategies (GBRS; i.e., strategies in which players cooperate only when a sufficient number of others do) are more effective than the strategy of unconditional defection (ALL-D) in 100-person social dilemmas. In this article, theoretical arguments and a replication of the Parks and Komorita simulations are presented, which demonstrate that when strategies are analyzed at the individual level (at which they were defined), GBRS are actually less effective than ALL-D. The divergence of this conclusion from that of Parks and Komorita is attributed to specific selection factors in design and analysis of the original simulations. However, when the strategies are analyzed as strategies for subgroups rather than individuals, the claim that GBRS are more effcetive than ALL-D finds more support, most notably because players using these and other conditionally cooperative strategies tend to defect when single or in small subgroups but to cooperate when in large subgroups.

Political Contestation and the Emergence of the Provincial People's Congresses as Power Players in Chinese Politics: A network explanation

In the process of institutionalizing themselves, the Chinese Provincial People's Congresses (PPCs) have used their power in a more assertive manner and even contested decisions from other more powerful institutions, as shown by cases from the past two decades. By presenting a network mode of governance, this paper argues that institutional linkages and reciprocal strategy have, respectively, featured the institution building of the PPCs and their interaction with other power players, and thus the tension between institutional development and the expansion of power for the PPCs was solved. These two goals were pursued simultaneously in the Chinese legislative development. This was made possible by the way in which the PPCs conducted their activities. In their contestation with other institutions, the leaders within the PPCs conscientiously followed a ‘Mohe’ strategy, i.e. competition-cum-cooperation, and expanded the legislative power without turning other political players into their stumbling blocks. The paper attributes this unique development to the choice-set defined by the changing environment of the political economy under reform and Deng Xiaoping's ideas, the institutional linkages within the system of the people's congresses, and the astute leadership of the political entrepreneurs within the PPCs. This mixture of consultation and confrontation in the interactions between the PPCs and other major political institutions also indicated a change of political governance in China toward a network mode.

Female baboons do not raise the stakes but they give as good as they get

We used data from four chacma baboon, Papio cynocephalus ursinus, troops, living in two populations, to test the raise the stakes (RTS) strategy of reciprocity. Female baboons did not raise the stakes either within or across grooming bouts. Instead they time-matched grooming contributions and divided grooming into short episodes. In addition, analysis of the grooming behaviour of frequently versus infrequently grooming dyads did not reveal differences in grooming patterns predicted by the RTS strategy. We suggest time constraints preclude the escalation of grooming bout length as required by RTS; the data were more consistent with a strategy of give as good as you get. However, this strategy could not explain all the patterns observed, and we conclude that biological market theory represents a more appropriate framework for investigating female grooming dynamics than dyadic games based on the iterated prisoner's dilemma. We suggest that competitive altruism among individuals acts as a market force influencing an individual's value as a grooming partner.

Rethinking Welfare Rights: Reciprocity Norms, Reactive Attitudes, and the Political Economy of Welfare Reform

Rethinking Welfare Rights: Reciprocity Norms, Reactive Attitudes, and the Political Economy of Welfare Reform

Applicability of a "speed" congenic strategy to dissect blood pressure quantitative trait loci on rat chromosome 2.

The identification of any quantitative trait locus (QTL) via a genome scan is only the first step toward the ultimate goal of gene identification. The next step is the production of congenic strains by which the existence of a QTL may be verified and the implicated chromosomal region be reduced to a size applicable to positional cloning of the causal gene. We used a speed congenic breeding protocol previously verified in mice for 2 blood pressure QTLs on rat chromosome 2. Four congenic strains were produced through introgression of various segments of chromosome 2 from Wistar-Kyoto rats from Glasgow colonies [WKY((Gla)) rats] into the recipient stroke-prone spontaneously hypertensive rats from Glasgow colonies [SHRSP((Gla))], and vice versa. The number of backcross generations required for each strain to achieve complete homozygosity at 83 background genetic markers in a "best" male varied between 3 and 4. Transfer of the region of rat chromosome 2 containing both QTLs from WKY((Gla)) into an SHRSP((Gla)) genetic background lowered both baseline and salt-loaded systolic blood pressure by approximately 20 and approximately 40 mm Hg in male congenic rats compared with the SHRSP parental strain (F=53.4, P<0.005; F=28.0, P< 0.0005, respectively). In contrast, control animals for stowaway heterozygosity presented no deviation from the blood pressure values recorded for the SHRSP((Gla)), indicating that if such heterozygosity exists, its effect on blood pressure is negligible. A reciprocal strategy in which 1 or both QTLs on rat chromosome 2 were transferred from SHRSP((Gla)) into a WKY((Gla)) genetic background resulted in statistically significant but smaller blood pressure increases for 1 of these QTLs. These results confirm the existence of blood pressure QTLs on rat chromosome 2 and demonstrate the applicability of a speed congenic strategy in the rat and emphasize the important role of the genetic background.

Reciprocal Strategies for Large Groups

Reciprocal strategies have been shown to be effective in inducing long-term cooperation in social dilemmas involving small, but not large, groups. In this article, we argue that group-based reciprocal strategies (GBRS)--under which one reciprocates cooperative factions, not individuals, within the group--can induce cooperation in large groups. Results of two computer simulations of 100-member groups show that a GBRS accumulates a significantly larger payoff than do other commonly advocated mixed-motive strategies. A third simulation showed that the size of the cooperative faction is influenced by the nature of the payoff matrix; when there is considerable temptation to defect, one should cooperate only after a large number of others have done so, but if there is little temptation to defect, one should reciprocate the cooperative actions of a smaller faction. We also found that the use of a "win-cooperate, lose-defect" heuristic led to substantial total outcomes. Our results suggest several psychological factors are important in facilitating cooperation, yet need empirical study.

Intercultural Influence: A Study of Japanese Expatriate Managers in Canada

This study explored the nature of intercultural influence by examining the influence strategies of Japanese managers in Canada with their Canadian and Japanese subordinates. Theories of inter-group behavior and cultural differences were used to predict the influence strategies used by Japanese managers with subordinates from their own and another culture. There were significant differences in their strategies, which were associated with the national culture of their subordinates. Japanese managers used significantly more influence with Canadian than with Japanese subordinates, including strategies of assertiveness, reason, sanctions, upward appeal, and reciprocity. The structure of Japanese influence differed from that found in prior research. We discuss the implications of these differences for managers influencing subordinates across cultures.

Interpersonal Understanding Among Friends: A Case-Study of Two Young Boys Playing Checkers

Abstract This one-year case-study explored the development of interpersonal understanding in young children in a naturalistic setting. Subjects (two best-friend boys, aged 4 years, 5 months at the start of the study) were studied as they played checkers together in their preschool classroom at a university laboratory school. Ten classroom sessions of checkers, one laboratory session of checkers, and two laboratory sessions of a teacher-made board game were videotaped and transcribed. All interactions were coded according to Selman's conceptualization of Enacted Interpersonal Understanding, and all conflicts were isolated and coded for resolution. Results showed a decrease in impulsive strategies and an increase in reciprocal strategies from the beginning to the end of the year, an increased ability to resolve conflicts, and a decrease in the extent to which play sessions were dominated by conflict. Results also showed a difference between classroom sessions and laboratory sessions. Findings are discussed in terms of implications for early childhood teachers and care-givers.

Trust and Reactions to Messages of Intent in Social Dilemmas

This study examined how low- and high-trust individuals react to messages of intended behavior in a social dilemma situation. Subjects played a two-person prisoner's dilemma; the opponent was a reciprocal strategy programmed by the experimenter. During the game, subjects received a message stating that the opponent planned to be cooperative or competitive for the remainder of the game. In Study 1, low trusters reacted to the competitive message by decreasing cooperation but were unaffected by the cooperative message; high trusters reacted to the cooperative message by increasing cooperation but were unaffected by the competitive message. Study 2 showed that a period of unconditional, message-consistent behavior immediately after the message can make low and high trusters responsive to cooperative and competitive messages, respectively. However, the number of unconditional responses was crucial. The study also found that stated intention and message-inconsistent behavior affect perceptions of the opponent's trustworthiness.

No Strategy is Evolutionarily Stable in the Repeated Prisoner's Dilemma

Following the influential work of Axelrod, the repeated Prisoner's Dilemma game has become the theoretical gold standard for understanding the evolution of co-operative behavior among unrelated individuals. Using the game, several authors have found that a reciprocal strategy known as Tit for Tat ( TFT) has done quite well in a wide range of environments. TFT strategists start out co-operating and then do what the other player did on the previous move. Despite the success of TFT and similar strategies in experimental studies of the game, Boyd & Lorberbaum (1987, Nature, Lond. 327, 58) have shown that no pure strategy, including TFT, is evolutionarily stable in the sense that each can be invaded by the joint effect of two invading strategies when long-term interaction occurs in the repeated game and future moves are discounted. Farrell & Ware (1989, Theor. Popul. Biol. 36 , 161) have since extended these results to include finite mixes of pure strategies as well. Here, it is proven that no strategy is evolutionarily stable when long-term relationships are maintained in the repeated Prisoner's Dilemma and future moves are discounted. Namely, it is shown each completely probabilistic strategy (i.e. one that both co-operates and defects with positive probability after every sequence of behavior) may be invaded by a single deviant strategy. This completes the proof started by Boyd and Lorberbaum and extended by Farrell and Ware. This paper goes on to prove that no reactive strategy with a memory restricted to the opponent's preceding move is evolutionarily stable when there is no discounting of future moves. This is true despite the success of a more forgiving variant of TFT called GTFT in a recent tournament among reactive strategies conducted by Nowak & Sigmund (1992, Nature 355 , 250) where future moves were not discounted. GTFT, for example, may be invaded by a pair of reactive mutants. Since no strategy is evolutionarily stable when future moves are discounted in the repeated game, the restriction of strategy types to those actually maintained by mutation and phenotypic and environmental variability in natural populations may be the key to understanding the evolution of co-operation. However, the result presented here that the somewhat realistic reactive strategies are also not evolutionarily stable at least in the non-discounted game suggests something else may be going on. For one, the proof that no reactive strategy is evolutionarily stable ironically shows the robustness of TFT -like strategies. Also, a significant invasion of strategies like GTFT (among reactive strategies) and TFT which can only be invaded by the joint effect of two deviant strategies relies on the maintenance of at least one of the mutants by recurrent mutation or other process. This weakens this paper's results somewhat. Further, it may be possible that some completely probabilistic strategies which are close to their pure counterparts may only be invadible by strategies with less "errors" in them: thus, a population may tend toward a pure strategy. Such findings could help explain the persistence of certain strategy types in the repeated PD when long-term interaction is possible.