Human cooperation based on punishment reputation.

The threat of punishment usually promotes cooperation. However, punishing itself is costly, rare in nonhuman animals, and humans who punish often finish with low payoffs in economic experiments. The evolution of punishment has therefore been unclear. Recent theoretical developments suggest that punishment has evolved in the context of reputation games. We tested this idea in a simple helping game with observers and with punishment and punishment reputation (experimentally controlling for other possible reputational effects). We show that punishers fully compensate their costs as they receive help more often. The more likely defection is punished within a group, the higher the level of within-group cooperation. These beneficial effects perish if the punishment reputation is removed. We conclude that reputation is key to the evolution of punishment.

Working memory constrains human cooperation in the Prisoner’s Dilemma

Many problems in human society reflect the inability of selfish parties to cooperate. The “Iterated Prisoner’s Dilemma” has been used widely as a model for the evolution of cooperation in societies. Axelrod’s computer tournaments and the extensive simulations of evolution by Nowak and Sigmund and others have shown that natural selection can favor cooperative strategies in the Prisoner’s Dilemma. Rigorous empirical tests, however, lag behind the progress made by theorists. Clear predictions differ depending on the players’ capacity to remember previous rounds of the game. To test whether humans use the kind of cooperative strategies predicted, we asked students to play the iterated Prisoner’s Dilemma game either continuously or interrupted after each round by a secondary memory task (i.e., playing the game “Memory”) that constrained the students’ working-memory capacity. When playing without interruption, most students used “Pavlovian” strategies, as predicted, for greater memory capacity, and the rest used “generous tit-for-tat” strategies. The proportion of generous tit-for-tat strategies increased when games of Memory interfered with the subjects’ working memory, as predicted. Students who continued to use complex Pavlovian strategies were less successful in the Memory game, but more successful in the Prisoner’s Dilemma, which indicates a trade-off in memory capacity for the two tasks. Our results suggest that the set of strategies predicted by game theorists approximates human reality.

Human cooperation in the simultaneous and the alternating Prisoner's Dilemma: Pavlov versus Generous Tit-for-Tat.

The iterated Prisoner's Dilemma has become the paradigm for the evolution of cooperation among egoists. Since Axelrod's classic computer tournaments and Nowak and Sigmund's extensive simulations of evolution, we know that natural selection can favor cooperative strategies in the Prisoner's Dilemma. According to recent developments of theory the last champion strategy of "win--stay, lose--shift" ("Pavlov") is the winner only if the players act simultaneously. In the more natural situation of players alternating the roles of donor and recipient a strategy of "Generous Tit-for-Tat" wins computer simulations of short-term memory strategies. We show here by experiments with humans that cooperation dominated in both the simultaneous and the alternating Prisoner's Dilemma. Subjects were consistent in their strategies: 30% adopted a Generous Tit-for-Tat-like strategy, whereas 70% used a Pavlovian strategy in both the alternating and the simultaneous game. As predicted for unconditional strategies, Pavlovian players appeared to be more successful in the simultaneous game whereas Generous Tit-for-Tat-like players achieved higher payoffs in the alternating game. However, the Pavlovian players were smarter than predicted: they suffered less from defectors and exploited cooperators more readily. Humans appear to cooperate either with a Generous Tit-for-Tat-like strategy or with a strategy that appreciates Pavlov's advantages but minimizes its handicaps.

The evolutionary origins of human patience: temporal preferences in chimpanzees, bonobos, and human adults.

To make adaptive choices, individuals must sometimes exhibit patience, forgoing immediate benefits to acquire more valuable future rewards [1-3]. Although humans account for future consequences when making temporal decisions [4], many animal species wait only a few seconds for delayed benefits [5-10]. Current research thus suggests a phylogenetic gap between patient humans and impulsive, present-oriented animals [9, 11], a distinction with implications for our understanding of economic decision making [12] and the origins of human cooperation [13]. On the basis of a series of experimental results, we reject this conclusion. First, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes) exhibit a degree of patience not seen in other animals tested thus far. Second, humans are less willing to wait for food rewards than are chimpanzees. Third, humans are more willing to wait for monetary rewards than for food, and show the highest degree of patience only in response to decisions about money involving low opportunity costs. These findings suggest that core components of the capacity for future-oriented decisions evolved before the human lineage diverged from apes. Moreover, the different levels of patience that humans exhibit might be driven by fundamental differences in the mechanisms representing biological versus abstract rewards.

The Evolution of Extreme Cooperation via Shared Dysphoric Experiences

Willingness to lay down one’s life for a group of non-kin, well documented in the
historical and ethnographic records, represents an evolutionary puzzle. Here we
present a novel explanation for the willingness to fight and die for a group, combining evolutionary theorizing with empirical evidence from real-world human groups. Building on research in social psychology, we develop a mathematical model showing how conditioning cooperation on previous shared experience can allow extreme (i.e., life-threatening) pro-social behavior to evolve. The model generates a series of predictions that we then test empirically in a range of special sample populations (including military veterans, college fraternity/sorority members, football fans, martial arts practitioners, and twins). Our results show that sharing painful experiences produces “identity fusion” – a visceral sense of oneness – more so even than bonds of kinship, in turn motivating extreme pro-group behavior, including willingness to fight and die for the group. These findings have theoretical and practical relevance. Theoretically, our results speak to the origins of human cooperation, as we offer an explanation of extremely costly actions left unexplained by existing models.
Practically, our account of how shared dysphoric experiences produce identity fusion, which produces a willingness to fight and die for a non-kin group, helps us better understand such pressing social issues as suicide terrorism, holy wars, sectarian violence, gang-related violence, and other forms of intergroup conflict.

Competition for Cooperation: variability, benefits and heritability of relational wealth in hunter-gatherers

Many defining human characteristics including theory of mind, culture and language relate to our sociality, and facilitate the formation and maintenance of cooperative relationships. Therefore, deciphering the context in which our sociality evolved is invaluable in understanding what makes us unique as a species. Much work has emphasised group-level competition, such as warfare, in moulding human cooperation and sociality. However, competition and cooperation also occur within groups; and inter-individual differences in sociality have reported fitness implications in numerous non-human taxa. Here we investigate whether differential access to cooperation (relational wealth) is likely to lead to variation in fitness at the individual level among BaYaka hunter-gatherers. Using economic gift games we find that relational wealth: a) displays individual-level variation; b) provides advantages in buffering food risk, and is positively associated with body mass index (BMI) and female fertility; c) is partially heritable. These results highlight that individual-level processes may have been fundamental in the extension of human cooperation beyond small units of related individuals, and in shaping our sociality. Additionally, the findings offer insight in to trends related to human sociality found from research in other fields such as psychology and epidemiology.

Cancer: an emergent property of disturbed resource-rich environments? Ecology meets personalized medicine

For an increasing number of biologists, cancer is viewed as a dynamic system governed by evolutionary and ecological principles. Throughout most of human history, cancer was an uncommon cause of death and it is generally accepted that common components of modern culture, including increased physiological stresses and caloric intake, favor cancer development. However, the precise mechanisms for this linkage are not well understood. Here, we examine the roles of ecological and physiological disturbances and resource availability on the emergence of cancer in multicellular organisms. We argue that proliferation of 'profiteering phenotypes' is often an emergent property of disturbed, resource-rich environments at all scales of biological organization. We review the evidence for this phenomenon, explore it within the context of malignancy, and discuss how this ecological framework may offer a theoretical background for novel strategies of cancer prevention. This work provides a compelling argument that the traditional separation between medicine and evolutionary ecology remains a fundamental limitation that needs to be overcome if complex processes, such as oncogenesis, are to be completely understood.

Fatores que influenciam a cooperação em humanos

Human cooperation is fundamentally affected by reciprocal exchange, but it is also remarkably common on the context of large and symbolically marked in-groups, which promote cooperation through the feeling of belonging to a group. In this thesis, two empirical articles were produced in order to investigate how human cooperation is affected by factors such as reciprocity, in-group behavior, in-group markers and gender. We investigated this subject through the administration of online games consisting of token donations, on which the subjects faced virtual players controlled by the experiment. We found that cooperative behavior is strongly influenced by reciprocity, and it is also affected by the in-group behavior, observed on the context of the social variables place of birth, ethnicity, and religions, once all of them acted as in-group markers. The subjects´ in-group behavior was enhanced when they played with generous in-group opponents, but weakened when their in-group opponents were non-generous. It was also found that cooperation is not affected by gender, but men and women cooperated in different ways under the influence of reciprocity and in-group behavior. Women are much more reciprocal on their cooperative behavior and men are less willing to cooperate with outgroupers, even when they act generously. The overall results contribute to a better understanding of the adaptive value of cooperation, reciprocity and in-group behavior on the solution of important challenges through the human evolutionary history

A influência do feedback verbal na cooperação em crianças

Human cooperation is a hallmark of this species due to its wide extension to genetically unrelated individuals and complex division of labor. It is considered an evolutionary puzzle, because the theory of evolution by natural selection predicts that self-interested individuals tend to be selected. Different theories have been proposed to explain the evolution of cooperation, which the most important are kin selection and reciprocal altruism. Considering the evolutionary continuity between species, humans and other primates have several common traits that help to promote cooperation between individuals of these species. Two features, however, seem to be particularly humans: inequality aversion and preferences in relation to others. Although human cooperation is not necessarily related to morality, cooperative traits are the basis for moral tendencies. The development of human morality is a combination of early prosocial tendencies, cooperative skills displayed at different ages, social learning and cultural transmission of norms. The social stimulus seems to be particularly important in promoting cooperative behavior in children and adults. In order to study the influence of social stimuli, as verbal feedback, on children cooperation, a study was conducted with children in a public goods game. 407 children from public schools in Natal / RN, divided into 21 groups, between six and nine years, participated in eight rounds of this game. After each round, seven groups received praise for larger donations, seven groups have been criticized by smaller donations, and the other seven received no comment. Children cooperated more when criticized, without significant differences between sexes, although young children have cooperated more negative than older children. The results are likely related to the anticipation and avoidance of punishment associated with the feedback (although this did not occur), and greater sensitivity to the authority in younger children. Nevertheless, the cooperation decreased in all groups until the last day of play. The results suggest an early sensitivity to moral punishment, whose role in the maintenance of social relations must have been important in the evolution of cooperation in humans

Merre vezessen a magyar kapitalizmus útja? Látkép Ronald Coase világítótornyából = Which course for Hungary s capitalism? A view from Ronald Coase s lighthouse

A tanulmány - amely Coase és az új intézményi közgazdaságtan alapján keresi a címbeli kérdésre adható választ - a kapitalizmus alapvető interakciós formájaként a kölcsönösen előnyös cserét azonosítja, amely az emberi együttműködés megnyilvánulása. A gazdasági fejlődés feltétele e kooperáció költségeit csökkentő társadalmi játékszabályok, intézmények kialakítása. A jól működő kapitalizmus intézményi rendje sűrű és sokrétű, a részleteit tekintve időben és térben igen változó, jelentős részben nem állami, hanem magáneredetű. Ez a rend nem tervezhető meg, és jelenlegi tudásunk alapján nem is érthető meg konzisztens, összefüggő rendszerként. A magyar gazdaság fejlődési célját ezért nem lehet nemzetgazdasági szintű rendszerként vagy modellként megfogalmazni. A tényleges feladat az intézményi rend középszintű elemeinek fokozatos, kísérletező változtatása, figyelembe véve a már létező intézményi környezet történetileg adott, helyhez és időhöz kötött sajátosságait. De az intézményi "barkácsolásnak" mindvégig szem előtt kell tartania a kapitalizmus alapelvét: az önkéntes, kölcsönösen előnyös tranzakciók támogatását. _____ The study draws on Coase s lighthouse" of new institutional economics in addressing this question. It identifies mutually beneficial exchange, a manifestation of human cooperation, as the underlying form of interaction in capitalism, while stressing that economic development depends on creating social rules of the game (institutions) that decrease the costs of exchange. The institutional order of well-functioning capitalism is thickly woven with many features, often of private rather than public (legal or political) origin. Details vary greatly in time and space. Such an order cannot be planned, and with current knowledge, it cannot be seen as a consistent system. So the goal in Hungary s economic development should not be defined as a system or model for a national economy. It should set out to change intermediate-level institutions in gradual, experimental ways that pay heed to the time and space-bound idiosyncrasies of existing ones. Moreover institutional tinkering" should observe capitalism s basic institutional principle: facilitation of voluntary, mutually beneficial transactions.

La notion de l’explosion de la coopération et ses implications chez Kim Sterelny.

Le concept de coopération est souvent utilisé dans le domaine de l’éthique et de la politique pour illustrer et comprendre l’alignement des comportements associatifs entre les êtres humains. En lien avec ce concept, notre recherche portera sur la première question de savoir si Kim Sterelny (2003) réussit à produire un modèle théorique permettant d’expliquer les origines et les mécanismes de la coopération humaine. Notre recherche portera aussi sur la deuxième question de savoir s’il arrive à se servir de ce modèle pour infirmer la thèse de la modularité massive. Ainsi, ce mémoire traitera successivement du problème de la coopération, de la théorie de la sélection de groupe, du déclencheur écologique de la coopération des hominidés, des notions de coalition, d’exécution et d’engagement et finalement de la thèse de la modularité massive. Par l’examen de ces sujets, nous souhaitons démontrer que Sterelny n’arrive qu’à fournir une esquisse probable des origines et du développement de la coopération humaine et que sa critique de la thèse de la modularité massive n’arrive pas à infirmer cette dernière.

La notion de l’explosion de la coopération et ses implications chez Kim Sterelny

Le concept de coopération est souvent utilisé dans le domaine de l’éthique et de la politique pour illustrer et comprendre l’alignement des comportements associatifs entre les êtres humains. En lien avec ce concept, notre recherche portera sur la première question de savoir si Kim Sterelny (2003) réussit à produire un modèle théorique permettant d’expliquer les origines et les mécanismes de la coopération humaine. Notre recherche portera aussi sur la deuxième question de savoir s’il arrive à se servir de ce modèle pour infirmer la thèse de la modularité massive. Ainsi, ce mémoire traitera successivement du problème de la coopération, de la théorie de la sélection de groupe, du déclencheur écologique de la coopération des hominidés, des notions de coalition, d’exécution et d’engagement et finalement de la thèse de la modularité massive. Par l’examen de ces sujets, nous souhaitons démontrer que Sterelny n’arrive qu’à fournir une esquisse probable des origines et du développement de la coopération humaine et que sa critique de la thèse de la modularité massive n’arrive pas à infirmer cette dernière.

Cooperation of Notch and Ras/MAPK signaling pathways in human breast carcinogenesis

Background: Recent studies have implicated aberrant Notch signaling in breast cancers. Yet, relatively little is known about the pattern of expression of various components of the Notch pathway, or its mechanism of action. To better understand the role of the Notch pathway in breast cancer, we have undertaken a detailed expression analysis of various Notch receptors, their ligands, and downstream targets at different stages of breast cancer progression. Results: We report here that there is a general increase in the expression levels of Notch 1, 2, 4, Jagged1, Jagged2, and Delta-like 4 proteins in breast cancers, with simultaneous upregulation of multiple Notch receptors and ligands in a given cancer tissue. While Notch3 and Delta-like1 were undetectable in normal tissues, moderate to high expression was detected in several cancers. We detected the presence of active, cleaved Notch1, along with downstream targets of the Notch pathway, Hes1/Hes5, in similar to 75% of breast cancers, clearly indicating that in a large proportion of breast cancers Notch signaling is aberrantly activated. Furthermore, we detected cleaved Notch1 and Hes1/5 in early precursors of breast cancers - hyperplasia and ductal carcinoma in situ suggesting that aberrant Notch activation may be an early event in breast cancer progression. Mechanistically, while constitutively active Notch1 alone failed to transform immortalized breast cells, it synergized with the Ras/MAPK pathway to mediate transformation. This cooperation is reflected in vivo, as a subset of cleaved Notch positive tumors additionally expressed phopsho-Erk1/2 in the nuclei. Such cases exhibited high node positivity, suggesting that Notch-Ras cooperation may lead to poor prognosis. Conclusions: High level expression of Notch receptors and ligands, and its increased activation in several breast cancers and early precursors, places Notch signaling as a key player in breast cancer pathogenesis. Its cooperation with the Ras/MAPK pathway in transformation offers combined inhibition of the two pathways as a new modality for breast cancer treatment.

Robot navigation in dense crowds : statistical models and experimental studies of human robot cooperation

This thesis explores the problem of mobile robot navigation in dense human crowds. We begin by considering a fundamental impediment to classical motion planning algorithms called the freezing robot problem: once the environment surpasses a certain level of complexity, the planner decides that all forward paths are unsafe, and the robot freezes in place (or performs unnecessary maneuvers) to avoid collisions. Since a feasible path typically exists, this behavior is suboptimal. Existing approaches have focused on reducing predictive uncertainty by employing higher fidelity individual dynamics models or heuristically limiting the individual predictive covariance to prevent overcautious navigation. We demonstrate that both the individual prediction and the individual predictive uncertainty have little to do with this undesirable navigation behavior. Additionally, we provide evidence that dynamic agents are able to navigate in dense crowds by engaging in joint collision avoidance, cooperatively making room to create feasible trajectories. We accordingly develop interacting Gaussian processes, a prediction density that captures cooperative collision avoidance, and a "multiple goal" extension that models the goal driven nature of human decision making. Navigation naturally emerges as a statistic of this distribution.

Most importantly, we empirically validate our models in the Chandler dining hall at Caltech during peak hours, and in the process, carry out the first extensive quantitative study of robot navigation in dense human crowds (collecting data on 488 runs). The multiple goal interacting Gaussian processes algorithm performs comparably with human teleoperators in crowd densities nearing 1 person/m², while a state of the art noncooperative planner exhibits unsafe behavior more than 3 times as often as the multiple goal extension, and twice as often as the basic interacting Gaussian process approach. Furthermore, a reactive planner based on the widely used dynamic window approach proves insufficient for crowd densities above 0.55 people/m². We also show that our noncooperative planner or our reactive planner capture the salient characteristics of nearly any dynamic navigation algorithm. For inclusive validation purposes, we show that either our non-interacting planner or our reactive planner captures the salient characteristics of nearly any existing dynamic navigation algorithm. Based on these experimental results and theoretical observations, we conclude that a cooperation model is critical for safe and efficient robot navigation in dense human crowds.

Finally, we produce a large database of ground truth pedestrian crowd data. We make this ground truth database publicly available for further scientific study of crowd prediction models, learning from demonstration algorithms, and human robot interaction models in general.