Social learning in cooperative dilemmas

Helping is a cornerstone of social organization and commonplace in human societies. A major challenge for the evolutionary sciences is to explain how cooperation is maintained in large populations with high levels of migration, conditions under which cooperators can be exploited by selfish individuals. Cultural group selection models posit that such large-scale cooperation evolves via selection acting on populations among which behavioural variation is maintained by the cultural transmission of cooperative norms. These models assume that individuals acquire cooperative strategies via social learning. This assumption remains empirically untested. Here, I test this by investigating whether individuals employ conformist or payoff-biased learning in public goods games conducted in 14 villages of a forager–horticulturist society, the Pahari Korwa of India. Individuals did not show a clear tendency to conform or to be payoff-biased and are highly variable in their use of social learning. This variation is partly explained by both individual and village characteristics. The tendency to conform decreases and to be payoff-biased increases as the value of the modal contribution increases. These findings suggest that the use of social learning in cooperative dilemmas is contingent on individuals'' circumstances and environments, and question the existence of stably transmitted cultural norms of cooperation.     

Spatial effects in social dilemmas

Social dilemmas and the evolutionary conundrum of cooperation are traditionally studied through various kinds of game theoretical models such as the prisoner's dilemma, public goods games, snowdrift games or by-product mutualism. All of them exemplify situations which are characterized by different degrees of conflicting interests between the individuals and the community. In groups of interacting individuals, cooperators produce a common good benefitting the entire group at some cost to themselves, whereas defectors attempt to exploit the resource by avoiding the costly contributions. Based on synergistic or discounted accumulation of cooperative benefits a unifying theoretical framework was recently introduced that encompasses all games that have traditionally been studied separately (Hauert, Michor, Nowak, Doebeli, 2005. Synergy and discounting of cooperation in social dilemmas. J. Theor. Biol., in press.). Within this framework we investigate the effects of spatial structure with limited local interactions on the evolutionary fate of cooperators and defectors. The quantitative effects of space turn out to be quite sensitive to the underlying microscopic update mechanisms but, more general, we demonstrate that in prisoner's dilemma type interactions spatial structure benefits cooperation-although the parameter range is quite limited-whereas in snowdrift type interactions spatial structure may be beneficial too, but often turns out to be detrimental to cooperation.     

Counseling dilemmas in EEC syndrome

In this report we describe a prenatally diagnosed case with four-limb ectrodactyly and cleft lip/palate. The family history reveals three-generation oligodontia. The difficulties in counseling of the families with EEC syndrome are discussed.     

Ethical dilemmas in malaria control.

Because the term "malaria control" specifies an anti-malaria activity rather than an outcome of that action, progress has been evaluated in terms of the effort expended. Plans that specify goals and time lines tend to lack irreversible endpoints. Anti-malaria interventions that are stimulated by economic considerations focus on sites in which the residents enjoy some employment advantage, while interventions based on humanitarian objectives serve the neediest residents of broad regions. Site-specific interventions are conducted by industrial or municipal agencies, while regional interventions are conducted by public agencies. Industry contributes an element of sustainability by injecting the possibility of gainful employment into the site. Efforts that distribute assets mainly to the richest-of-the-poor may fail to preserve lives that would otherwise have been preserved, while those that serve the poorest-of-the-poor may fail to create sustainable cycles of health and wealth. Progress in relieving the burden imposed by malaria requires economically motivated as well as humanitarian contributions, and both should specify realistically time-limited goals that ultimately permit deintensification.     

Human adoption in evolutionary perspective

Exploitation is a fundamental element of the parental strategies of many species of birds. Cuckoos, for example, lay their eggs in the nest of other birds, who often unwittingly rear the alien nestlings as their own. Nest parasitism is an efficient reproductive strategy for cuckoos, who do not have to worry about building a nest, incubating their eggs, or feeding their nestlings. But not all hosts respond passively to such intrusions. In response to parasitic cowbirds, for example, robins have evolved the ability to detect and selectively eject alien young from their nests. Human parenting strategies differ sharply from the strategies of cuckoos and robins. Unlike cuckoos, we are reluctant to allow our children to be raised by others. Unlike robins, we knowingly rear strange young. What makes human behavior toward children so different from that of cuckoos and robins? Humans seem to share a number of predispositions that facilitate successful adoptive relationships, and the desire to raise children seems to be pervasive among modern humans. Despite these commonalities, patterns of adoption transactions vary greatly among contemporary human societies. This paper considers the origins and causes of cross-cultural variation in human adoptive behavior from an evolutionary perspective.     

What is new in adoption

Adoptions arranged through adoption agencies are on the increase because there are more agencies. The Citizens Committee on Adoption of Children in California has concluded that there are very few adoptable children under care in orphanages. Fifty per cent of physicians would prefer agency adoptions, but only 24 per cent actually refer both expectant mothers needing such services and couples wishing to adopt infants to such agencies. The program in this field of social welfare should be child-centered and physicians should seek and give cooperation to such agencies.     

Social observation increases deontological judgments in moral dilemmas

A concern for positive reputation is one of the core motivations underlying various social behaviors in humans. The present study investigated how experimentally induced reputation concern modulates judgments in moral dilemmas. In a mixed-design experiment, participants were randomly assigned to the observed vs. the control group and responded to a series of trolley-type moral dilemmas either in the presence or absence of observers, respectively. While no significant baseline difference in personality traits and moral decision tendency were found across two groups of participants, our analyses revealed that social observation promoted deontological judgments especially for moral dilemmas involving direct bodily harm (i.e., personal moral dilemmas), yet with an overall decrease in decision confidence and significant prolongation of reaction time. Moreover, participants in the observed group, but not in the control group, showed the increased sensitivities towards warmth vs. competence traits words in the lexical decision task performed after the moral dilemma task. Our findings suggest that reputation concern, once triggered by the presence of potentially judgmental others, could activate a culturally dominant norm of warmth in various social contexts. This could, in turn, induce a series of goal-directed processes for self-presentation of warmth, leading to increased deontological judgments in moral dilemmas. The results of the present study provide insights into the reputational consequences of moral decisions that merit further exploration.     

Strategic dilemmas of biosecurity in the European Union

Systems for societal/homeland security in both Europe and the United States are in flux to adjust to 21st century threats, such as terrorism, the proliferation of weapons of mass destruction, regional conflicts, state failures, and organized crime. It is important that reforms take place on both sides of the Atlantic that recognize the interdependence of Europe and the United States. Security, including biosecurity, for Europe is strongly connected to security in the U.S. Diseases transcend borders, and their consequences can be the same, irrespective of where the outbreak occurs or whether it is a natural occurrence or an act of bioterrorism. This article examines the political and strategic dilemmas and complexities that would confront the European Union (EU) in the event of a bioterrorism attack or a naturally occurring outbreak. Although several initiatives have been taken by the 15 member states and within the EU Commission, the EU is not institutionally prepared for transnational, rapidly moving diseases that could cause grave consequences in Europe and other regions, including the U.S. The prime responsibility for protecting European citizens against outbreaks rests with each member state. However, with intertwined and open European societies, the consequences would likely spill across borders. The EU Commission would have to become involved because such aspects as the internal market and freedom of movement would be affected. Responsibility, but not authority, would be pushed to the top. A coordinated EU response to such crises depends on European political leadership.     

From local to global dilemmas in social networks

Social networks affect in such a fundamental way the dynamics of the population they support that the global, population-wide behavior that one observes often bears no relation to the individual processes it stems from. Up to now, linking the global networked dynamics to such individual mechanisms has remained elusive. Here we study the evolution of cooperation in networked populations and let individuals interact via a 2-person Prisoner's Dilemma--a characteristic defection dominant social dilemma of cooperation. We show how homogeneous networks transform a Prisoner's Dilemma into a population-wide evolutionary dynamics that promotes the coexistence between cooperators and defectors, while heterogeneous networks promote their coordination. To this end, we define a dynamic variable that allows us to track the self-organization of cooperators when co-evolving with defectors in networked populations. Using the same variable, we show how the global dynamics--and effective dilemma--co-evolves with the motifs of cooperators in the population, the overall emergence of cooperation depending sensitively on this co-evolution.     

Synergy and discounting of cooperation in social dilemmas

The emergence and maintenance of cooperation by natural selection is an enduring conundrum in evolutionary biology, which has been studied using a variety of game theoretical models inspired by different biological situations. The most widely studied games are the Prisoner's Dilemma, the Snowdrift game and by-product mutualism for pairwise interactions, as well as Public Goods games in larger groups of interacting individuals. Here, we present a general framework for cooperation in social dilemmas in which all the traditional scenarios can be recovered as special cases. In social dilemmas, cooperators provide a benefit to the group at some cost, while defectors exploit the group by reaping the benefits without bearing the costs of cooperation. Using the concepts of discounting and synergy for describing how benefits accumulate when more than one cooperator is present in a group of interacting individuals, we recover the four basic scenarios of evolutionary dynamics given by (i) dominating defection, (ii) coexistence of defectors and cooperators, (iii) dominating cooperation and (iv) bi-stability, in which cooperators and defectors cannot invade each other. Generically, for groups of three or more interacting individuals further, more complex, dynamics can occur. Our framework provides the first unifying approach to model cooperation in different kinds of social dilemmas.     

Methodological dilemmas: gatekeepers and positionality in Bradford

This paper explores the ever-evolving relationship between gatekeepers and the researcher, and the ways in which it may facilitate, constrain or transform the research process by opening and/or closing the gate. We explore the methodological issue of positionality and discuss the ways in which gatekeepers drew on different axes of the researcher's identities – religion, ethnicity, gender and age – in ambiguous and contradictory ways. In analysing this relationship, we locate the discussion within its historical context, as we contend that contextuality influenced the way gatekeepers positioned the researcher. This paper draws on the field experiences of the first author in four inner-city neighbourhoods in Bradford, West Yorkshire, a northern city with a well-established Pakistani Muslim community that has become synonymous with the Rushdie affair and the 1995 and 2001 urban disturbances.