Cooperation and self-interest: Pareto-inefficiency of Nash equilibria in finite random games

The relative merits of cooperation and self-interest in an ensemble of strategic interactions can be investigated by using finite random games. In finite random games, finitely many players have finite numbers of actions and independently and identically distributed (iid) random payoffs with continuous distribution functions. In each realization, players are shown the values of all payoffs and then choose their strategies simultaneously. Noncooperative self-interest is modeled by Nash equilibrium (NE). Cooperation is advantageous when a NE is Pareto-inefficient. In ordinal games, the numerical value of the payoff function gives each player's ordinal ranking of payoffs. For a fixed number of players, as the number of actions of any player increases, the conditional probability that a pure strategic profile is not pure Pareto-optimal, given that it is a pure NE, apparently increases, but is bounded above strictly below 1. In games with transferable utility, the numerical payoff values may be averaged across actions (so that mixed NEs are meaningful) and added across players. In simulations of two-player games when both players have small, equal numbers of actions, as the number of actions increases, the probability that a NE (pure and mixed) attains the cooperative maximum declines rapidly; the gain from cooperation relative to the Nash high value decreases; and the gain from cooperation relative to the Nash low value rises dramatically. In the cases studied here, with an increasing number of actions, cooperation is increasingly likely to become advantageous compared with pure self-interest, but self-interest can achieve all that cooperation could achieve in a nonnegligible fraction of cases. These results can be interpreted in terms of cooperation in societies and mutualism in biology.     

Reply to Messick and Jackson's comments on authoritarianism or acquiescence.

The author replies to comments made by Messick and Jackson (see record 1959-05766-001) on his original article "Authoritarianism or Acquiescence" (see record 1957-02534-001). The author states that in light of Messick and Jackson's corrections, for which the author is grateful, and subsequent independent studies on the same subject, it appears that the hypothesis advanced in in "Authoritarianism or Acquiescence" was more satisfactory than the analysis used to test the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social value orientations and impressions of partner's honesty and intelligence: A test of the might versus morality effect.

This research evaluates the might vs morality effect (W. B. G. Liebrand et al; see record 1987-34399-001) by examining whether the manipulation of the perception of partner's honesty and intelligence interacts with the observer's own social value orientation to influence the latter's expectations regarding partner cooperation and own cooperation in a social dilemma. Results reveal that greater cooperation was expected from an honest partner than from a dishonest partner and that this effect was stronger for prosocial Ss than for individualists and competitors. Conversely, individualists and competitors expected greater cooperation from an unintelligent partner than from an intelligent partner, whereas prosocial Ss did not expect differences between these partners. Similar findings were obtained for own cooperation, although social value orientations did not interact with partner intelligence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Democracy under uncertainty: The wisdom of crowds and the free-rider problem in group decision making.

We introduce a game theory model of individual decisions to cooperate by contributing personal resources to group decisions versus by free riding on the contributions of other members. In contrast to most public-goods games that assume group returns are linear in individual contributions, the present model assumes decreasing marginal group production as a function of aggregate individual contributions. This diminishing marginal returns assumption is more realistic and generates starkly different predictions compared to the linear model. One important implication is that, under most conditions, there exist equilibria where some, but not all, members of a group contribute, even with completely self-interested motives. An agent-based simulation confirmed the individual and group advantages of the equilibria in which behavioral asymmetry emerges from a game structure that is a priori perfectly symmetric for all agents (all agents have the same payoff function and action space but take different actions in equilibria). A behavioral experiment demonstrated that cooperators and free riders coexist in a stable manner in groups performing with the nonlinear production function. A collateral result demonstrated that, compared to a dictatorial decision scheme guided by the best member in a group, the majority/plurality decision rules can pool information effectively and produce greater individual net welfare at equilibrium, even if free riding is not sanctioned. This is an original proof that cooperation in ad hoc decision-making groups can be understood in terms of self-interested motivations and that, despite the free-rider problem, majority/plurality decision rules can function robustly as simple, efficient social decision heuristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The shifting definitions of acquiescence.

Asserts that the P.M. Bentler, D.N. Jackson, and S. Messick (see record 1972-21017-001) rebuttal is not responsive to the criticisms leveled earlier. The shifting over the years in the definition of acquiescence and in the kinds of evidence used to bolster the acquiescence interpretation is noted. In particular, it is noted tht highly specific and replicable evidence is required to support the presently advanced hypothesis that acceptance acquiescence importantly influences assessment procedures. The Bentler, et al., view that any evidence of response inconsistency is evidence for their "distinct species of acquiescence" is not accepted. (l8 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychotherapy and the twelve step approach for substance abusers: The limits of integration.

Argues that while there is potential for successful blending of 12-step approaches and psychotherapies for chemical dependency at the level of helping strategies/techniques, some basic differences in values and philosophy will make it impossible to ever fully integrate the 2 approaches without compromising one or the other approach. Some of the differences between the 2 approaches involve leadership (indigenous vs professional), individual control (increasing vs decreasing), and spirituality (enhanced vs decreased). Given that psychotherapy and the 12-step approach must remain largely independent, a model for interactions based on mutual respect, independent control, and cooperation is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The rate of antimony elimination from molten copper by the use of Na<Subscript>2</Subscript>CO<Subscript>3</Subscript> slag

The rate of Sb elimination from molten copper by the use of Na₂CO₃ slag was measured at 1523 K. The results obtained under the present experimental conditions show that Sb in molten copper is eliminated in a tri-valent or a penta-valent form, depending on the oxygen concentration at the slag-metal interface, and its elimination rate increases with increasing initial oxygen concentration in molten copper. The overall elimination rate of Sb is affected by the stirring condition of the molten copper, which indicates a rate control by mass transfer in that phase. The mass-transfer coefficients of Sb and oxygen in molten copper at 1523 K without external stirring were determined, respectively, to be

Response style: A psychologist's fallacy?

Analyzes the recent attempt by P. M. Bentler, D. N. Jackson, and S. Messick(see record 1972-03014-001) to revive the acquiescence hypothesis. It is shown that (a) they fail to clarify the conceptual meaning of response style; and (b) their operational definition of content responding and acquiescent styles employs, as did earlier studies of acquiescence, an incorrect logical model incorrect since it treats all opposites as formally equal instead of distinguishing between contraries and contradictories. While consequently an acquiescence interpretation of their data is gratuitous, these data fail to meet Bentler, et al.'s own criteria for response style. The root of the problem seems to be that the Es mistake their own interpretation, based on an oversimplified model, for the (actual or functional) item content and then define all discrepant responses as acquiescence a mistake of the sort called "the psychologist's fallacy" by W. James. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling of the atomic ordering processes in Fe<Subscript>3</Subscript>Al intermetallics by the monte carlo simulation method combined with electronic theory of alloys

The evolution of atomic ordering processes in Fe₃Al has been modeled by the Monte Carlo (MC) simulation method combined with the electronic theory of alloys in pseudopotential approximation. The magnitude of atomic ordering energies of atomic pairs in the Fe₃Al system has been calculated by means of electronic theory in pseudopotential approximation up to sixth coordination spheres and subsequently used as input data for MC simulation for more detailed analysis for the first time. The Bragg-Williams long-range order (LRO) and Cowley-Warren, short-range order (SRO) parameters have been calculated from the equilibrium configurations attained at the end of MC simulation for each predefined temperature and Al concentration levels, which reveal the evolution of the system from DO₃→B2→ disordered state as temperature, increases. The variation of ordering parameters with temperature has identified the transition temperature from DO₃→B2 type superlattice, and from B2→disordered (α) solid solution at about 540°C and >900 °C, respectively, showing good qualitative agreement with experimental results. The results of the present study imply that combination of electronic theory of alloys in pseudopotential approximation with MC simulation can be successfully applied for qualitative or semiquantitative analysis of energetical and structural characteristics of atomic ordering processes in Fe₃Al intermetallics.     

Face validity in psychological assessment: Implications for a unified model of validity.

Comments on S. Messick's (see record 1996-10004-001) paper on the validity of psychological assessment. R. F. Bornstein argues that the concept of face validity is missing from Messick's discussion of the validity literature and that no model of unified validity can be complete without it. According to Bornstein, integrating the concept of face validity into Messick's framework would not be difficult as it is directly related to at least 4 of the 6 components of unified validity described by Messick. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hydrogen absorption behavior of TA15 alloy

The hydrogen absorption kinetics of TA15 titanium alloy at 973-1123 K was studied using a tube-type hydrogen treatment furnace.The hydrogen absorption kinetic curves obtained were analyzed according to a series of mechanism equations to reveal the kinetic parameters and mechanism of the hydrogen absorption process. The results show that both the hydrogen absorption rate and the equilibrium hydrogen pressure increase and the time to reach equilibrium is shortened with increasing temperature. It is found that only the second hydrogen absorption period exists in the hydrogen absorption process of TA15 alloy between 973 and 1123 K, and the activation energy is 54.889kJ/mol for hydrogen absorption. X-ray diffiaction (XRD) and scanning electron microscopy (SEM) results demonstrate that δ hydride forms between 973 and 1123 K, and β phase decreases with the increase of temperature. Orthorhombic α" martensite is generated at 1073-1123 K,and their amount increases with increasing temperature.     

脆硫铅锑矿闪速熔炼过程热力学分析

基于最小吉布斯自由能原理,采用元素势法,研究建立了脆硫铅锑矿闪速熔炼过程多相平衡热力学模型,考察了吨矿氧量（OVPTC）、富氧浓度（OG）和熔炼温度（T）对铅与锑在各平衡产物中分配比的影响。结果表明,对一定成分的脆硫铅锑矿,铅在合金中的分配比随OVPTC的增大不断下降,随T的升高略有上升;锑在合金中的分配比随OVPTC的增大有所下降,随T的升高大幅上升;熔炼烟气量随OG的增大而大幅减少。综合考虑铅和锑的直收率,脆硫铅锑矿闪速熔炼应控制一定的OVPTC,适当提高OG和T。      

Game theory and reciprocity in some extensive form experimental games

We examine decision making in two-person extensive form game trees using nine treatments that vary matching protocol, payoffs, and payoff information. Our objective is to establish replicable principles of cooperative versus noncooperative behavior that involve the use of signaling, reciprocity, and backward induction strategies, depending on the availability of dominated direct punishing strategies and the probability of repeated interaction with the same partner. Contrary to the predictions of game theory, we find substantial support for cooperation under complete information even in various single-play treatments.     

"Interactive use of lexical information in speech perception": Correction to Connine and Clifton.

Reports an error in "Interactive use of lexical information in speech perception" by Cynthia M. Connine and Charles Clifton (Journal of Experimental Psychology: Human Perception and Performance, 1987[May], Vol 13[2], 291-299). In the aforementioned article, Figures 1 and 2 were inadvertently transposed. The figure on p. 294 is actually Figure 2, and the figure on p. 296 is actually Figure 1. The captions are correct as they stand. (The following abstract of the original article appeared in record 1987-23984-001.) Two experiments are reported that demonstrate contextual effects on identification of speech voicing continua. Experiment 1 demonstrated the infuence of lexical knowledge on identification of ambiguous tokens from word–nonword and nonword–word continua. Reaction times for word and nonword responses showed a word advantage only for ambiguous stimulus tokens (at the category boundary); no word advantage was found for clear stimuli (at the continua endpoints). Experiment 2 demonstrated an effect of a postperceptual variable, monetary payoff, on nonword–nonword continua. Identification responses were influenced by monetary payoff, but reaction times for bias-consistent and bias-inconsistent responses did not differ at the category boundary. An advantage for bias-consistent responses was evident at the continua endpoints. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

库水位骤降耦合不同类型降雨泥岩边坡渗透稳定性数值模拟研究

为研究泥岩边坡在库水位骤降与不同降雨类型耦合情况下的渗流特性和稳定性规律,基于岩体非饱和理论和Hoek-Brown准则,利用极限平衡理论推导出库水位与降雨耦合情况下的边坡稳定系数表达式,并利用Geo-slope软件对泥岩边坡进行数值模拟。结果表明：（1）库水位骤降情况下,孔压先减小后保持不变,监测点距库岸越远,孔压的变化幅度越小,边坡稳定系数随时间变化呈现先减小后增大,之后保持不变的规律,库水位下降速率越大,最小稳定系数越小,且其出现的时间越早;（2）不同静库水位耦合不同类型降雨情况下,孔压先增大后减小,静库水位越高,整体孔压越大;（3）库水位骤降偶遇降雨边坡内部的孔压逐渐减小,在降雨过程中陡然上升,当平均型降雨发生在库水位骤降第24~26 d时,最小稳定系数达到最小。该研究成果为正确认识降雨耦合库水位骤降情况下的岩质边坡稳定性规律提供了参考。     

Cooperative choice in N-person dilemma situation.

The N-person Prisoner's Dilemma game (N?≥?3), like the 2-person game, represents a situation in which an individual is faced with the conflict between maximizing personal gain and maximizing collective gain. The N-person case is a more general prototype of this conflict of motives than is the 2-person case and simulates many real-life problems such as energy conservation, environmental pollution, and overpopulation. Three experiments were conducted with a total of 424 male undergraduates to evaluate a model and an index of cooperative choice in N-person dilemma situations. The experiments compared 2 experimental procedures (multiple trials with and without feedback) and varied several parameters of the index: group size, slopes of the payoff functions for persons who cooperate or compete, and the intercept difference between these 2 functions. Results suggest 2 serious problems with the model: (a) The model is based on an index of cooperative choice that may be restricted to a situation in which the slopes of the payoff functions are equal; and (b) significant changes in cooperation were found in the study, and since it is a static model, it cannot account for such changes over trials. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"The effects of cooperation and competition on intrinsic motivation and performance": Correction to Tauer and Harackiewicz (2004).

Reports an error in "The Effects of Cooperation and Competition on Intrinsic Motivation and Performance" by John M. Tauer and Judith M. Harackiewicz (Journal of Personality and Social Psychology, 2004[Jun], Vol 86[6], 849-861). The article contained two errors. On page 853, in Table 1, Study 4, in the Task enjoyment row, the mean for the pure coop-4 condition, which is missing, should be 3.65, and the mean for the individual condition, shown as 3.65, should be 3.63. (The following abstract of the original article appeared in record 2004-14304-005.) The authors examined the effects of competition and cooperation on intrinsic motivation and performance in 4 studies. Across 3 behavioral studies that involved shooting a basketball, no differences were observed between competition and cooperation on task enjoyment or performance. However, the combination of competition and cooperation (intergroup competition) consistently led to higher levels of intrinsic motivation, and in 2 of the 3 studies, performance. In a questionnaire study, the authors replicated the positive effects of intergroup competition on enjoyment and examined process measures that might account for these effects. These findings suggest that competition and cooperation both have positive aspects and that structuring recreational activities to include both can facilitate high levels of both intrinsic motivation and performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expectancy theory prediction of the goal theory postulate, "The harder the goals, the higher the performance."

Goal theory postulates that harder goals lead to higher performance than do easier goals. The present study tested the prediction, based on expectancy valence theory, that this would be true only if the payoff for succeeding at the harder goal is sufficiently greater than the alternatives to compensate for its greater difficulty. 63 undergraduates were each given an easy and a hard task/goal, requiring the comparison of paired sets of 3-digit numbers. Expectancy theory measures for the 2 goals were obtained from Ss. Performance was higher for the hard goal than for the easy goal, supporting the goal theory postulate. Force was also higher for the hard goal than for the easy goal. In addition, force change across the 2 goals was associated with performance change, supporting the conclusion that expectancy valence theory can predict the goal theory postulate. The valence of goal attainment was higher for the hard goal than for the easy goal. Valence change across the 2 goals was associated with performance change to a greater degree than was expectancy change, suggesting that the attained performance difference can be attributed to the valence difference. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

110t不锈钢钢包炉底吹氩水模拟

依据相似原理建立钢包的物理模拟体系,采用水模型对110t LF钢包底吹氩过程进行研究,分析了吹气量、吹氩位置、钢包覆盖渣和钢包液面高度对钢包混匀的影响,并进行了相应的试验验证。研究结果表明：水模型试验结果和大工业应用具有较好的一致性,验证了水模型的可行性;钢包液面高度越高,混匀时间越长;吹气量越大,混匀时间越短;相同的液面高度和吹气量下,底吹氩最佳位置为0.33r 附近;钢包覆盖渣较黏时会使钢液流动显著减慢,增大吹气量容易产生卷渣现象。     

"Integrating neural networks into decision-making and motivational theory: Rethinking VIE theory": Erratum.

Reports an error in "Integrating neural networks into decision-making and motivational theory: Rethinking VIE theory" by Robert G. Lord, Paul J. Hanges and Ellen G. Godfrey (Canadian Psychology/Psychologie Canadienne, 2003[Feb], Vol 44[1], 21-38). The paper by Lord, Henges and Godfrey, referred to in some of the commentaries (this issue), was accepted as part of the Special Section on psychology without boundaries. However, it was inadvertently published in a previous issue. The full reference is: Lord, R. G., Hanges, P. J., & Godfrey, E. G. (2003). Integrating neural networks into decision-making and motivational theory: Rethinking VIE theory. Canadian Psychology, 44 (1), 21-38. (The following abstract of the original article appeared in record 2003-01537-005.) Uses a reformulation of V. H. Vroom's (1964) VIE (Valence-Instrumentality-Expectancy) theory to illustrate the potential value of neuropsychologically based models of cognitive processes. Vroom's theory posits that people's decisions are determined by their affective reactions to certain outcomes (valences), beliefs about the relationship between actions and outcomes (expectancies), and perceptions of the association between primary and secondary outcomes (instrumentalities). One of the major criticisms of this type of theory is that the computations it requires are unrealistically time-consuming and often exceed working memory capacity. In this paper, the authors maintain that if an individual has extensive experience with a problem situation, he or she can process decisions about that situation using neural networks that operate implicitly so that cognitive resources are not exhausted by simple computations; instead, the computations are performed implicitly by neural networks. By thinking about VIE from a neural network standpoint, at least one of its problems is eliminated, and several new insights into decision-making are provided. The authors use simulation methodology to show that such a model is both viable and can reflect the effects of current goals on choice processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)