@Article{Haidt07,
  author = 	 {Jonathan Haidt},
  title = 	 {The New Synthesis in Moral Psychology},
  journal = 	 {Science},
  year = 	 2007,
  volume =	 316,
  pages =	 {998--1002},
  annote =	 {People are selfish, yet morally motivated. Morality is
universal, yet culturally variable. Such apparent contradictions are
dissolving as research from many disciplines converges on a few shared
principles, including the importance of moral intuitions, the socially
functional (rather than truth-seeking) nature of moral thinking, and
the coevolution of moral minds with cultural practices and
institutions that create diverse moral communities. I propose a fourth
principle to guide future research: Morality is about more than harm
and fairness. More research is needed on the collective and religious
parts of the moral domain, such as loyalty, authority, and spiritual
purity.}
}

@article{DeMarzo05, 
  type={Working Paper Series},
  title={{Relative Wealth Concerns and Technology Bubbles}},
  author={Demarzo, Peter  M. and Kaniel, Ron  and Kremer, Ilan  },
  journal={SSRN eLibrary},
  year=2005,
  publisher={SSRN},
  keywords={Bubble, technology, relative wealth, Joneses, herding, over-investment},
  location={http://ssrn.com/paper=668137},
  note={\url{http://ssrn.com/paper=668137}},
  language={English}
} 


@article{Arrow63,
     jstor_articletype = {primary_article},
     title = {Uncertainty and the Welfare Economics of Medical Care},
     author = {Arrow, Kenneth J.},
     journal = {The American Economic Review},
     jstor_issuetitle = {},
     volume = {53},
     number = {5},
     jstor_formatteddate = {Dec., 1963},
     pages = {941--973},
     url = {http://www.jstor.org/stable/1812044},
     ISSN = {00028282},
     abstract = {},
     language = {},
     year = {1963},
     publisher = {American Economic Association},    
     copyright = {Copyright ¿ 1963 American Economic Association},
    }

@Article{CluttonBrock09:Cooperation,
  author = 	 {Tim Clutton-Brock},
  title = 	 {Cooperation Between Non-Kin in Animal Societies},
  journal = 	 {Nature},
  year = 	 2009,
  volume =	 462,
  pages =	 {51--57},
  annote =	 {Explanations of cooperation between non-kin in animal
  societies often suggest that individuals exchange resources or
  services and that cooperation is maintained by reciprocity. But do
  cooperative interactions between unrelated individuals in non-human
  animals really resemble exchanges or are they a consequence of
  simpler mechanisms? Firm evidence of reciprocity in animal societies
  is rare and many examples of cooperation between non-kin probably
  represent cases of intra-specific mutualism or manipulation.}
}

 

@article{Henrich10:MarketsReligionFairness,
author = {Henrich, Joseph and Ensminger, Jean and 
          McElreath, Richard and Barr, Abigail and 
          Barrett, Clark and Bolyanatz, Alexander and 
          Cardenas, Juan Camilo and Gurven, Michael and 
          Gwako, Edwins and Henrich, Natalie and 
          Lesorogol, Carolyn and Marlowe, Frank and 
          Tracer, David and Ziker, John},
title = {Markets, Religion, Community Size, 
         and the Evolution of Fairness and Punishment},
journal = {Science},
volume = {327},
number = {5972},
pages = {1480--1484},
doi = {10.1126/science.1182238},
year = {2010},
abstract = {Large-scale societies in which strangers regularly engage
in mutually beneficial transactions are puzzling. The evolutionary
mechanisms associated with kinship and reciprocity, which underpin
much of primate sociality, do not readily extend to large unrelated
groups. Theory suggests that the evolution of such societies may have
required norms and institutions that sustain fairness in ephemeral
exchanges. If that is true, then engagement in larger-scale
institutions, such as markets and world religions, should be
associated with greater fairness, and larger communities should punish
unfairness more. Using three behavioral experiments administered
across 15 diverse populations, we show that market integration
(measured as the percentage of purchased calories) positively covaries
with fairness while community size positively covaries with
punishment. Participation in a world religion is associated with
fairness, although not across all measures. These results suggest that
modern prosociality is not solely the product of an innate psychology,
but also reflects norms and institutions that have emerged over the
course of human history.},
eprint = {http://www.sciencemag.org/cgi/reprint/327/5972/1480.pdf}
}

@article{Hoff10,
author = {Hoff, Karla},
title = {Fairness in Modern Society},
journal = {Science},
volume = {327},
number = {5972},
pages = {1467--1468},
doi = {10.1126/science.1188537},
year = {2010},
eprint = {http://www.sciencemag.org/cgi/reprint/327/5972/1467.pdf}
}


@article{Woolley10012010,
author = {Woolley, Anita Williams and Chabris, Christopher F. 
          and Pentland, Alexander and Hashmi, Nada and Malone, Thomas W.},
title = {Evidence for a Collective Intelligence Factor in the 
         Performance of Human Groups},
journal = {Science},
pages = {science.1193147},
doi = {10.1126/science.1193147},
year = {2010},
abstract = {Psychologists have repeatedly shown that a single
statistical factor--often called "general intelligence"--emerges from
the correlations among people's performance on a wide variety of
cognitive tasks. But no one has systematically examined whether a
similar kind of "collective intelligence" exists for groups of
people. In two studies with 699 individuals, working in groups of two
to five, we find converging evidence of a general collective
intelligence factor that explains a group's performance on a wide
variety of tasks. This "c factor" is not strongly correlated with the
average or maximum individual intelligence of group members but is
correlated with the average social sensitivity of group members, the
equality in distribution of conversational turn-taking, and the
proportion of females in the group.},
}


@article{Stapel08042011,
  author = {Stapel, Diederik A. and Lindenberg, Siegwart}, 
  title = {Coping with Chaos: How Disordered Contexts Promote 
           Stereotyping and Discrimination}, 
  volume = 332, 
  number = 6026, 
  pages = {251--253}, 
  year = 2011, 
  doi = {10.1126/science.1201068}, 
  abstract ={Being the victim of discrimination can have serious
  negative health- and quality-of-lifeâ€“related
  consequences. Yet, could being discriminated against depend on such
  seemingly trivial matters as garbage on the streets? In this study,
  we show, in two field experiments, that disordered contexts (such as
  litter or a broken-up sidewalk and an abandoned bicycle) indeed
  promote stereotyping and discrimination in real-world situations
  and, in three lab experiments, that it is a heightened need for
  structure that mediates these effects (number of subjects: between
  40 and 70 per experiment). These findings considerably advance our
  knowledge of the impact of the physical environment on stereotyping
  and discrimination and have clear policy implications: Diagnose
  environmental disorder early and intervene immediately.},
  eprint = {http://www.sciencemag.org/content/332/6026/251.full.pdf}, 
  journal = {Science} 
}

@article{Freeman01:Libertarians,
     title = {Illiberal Libertarians: 
            Why Libertarianism Is Not a Liberal View},
     author = {Freeman, Samuel},
     journal = {Philosophy & Public Affairs},
     volume = 30,
     number = 2,
     jstor_formatteddate = {Spring, 2001},
     pages = {105--151},
     url = {http://www.jstor.org/stable/3557960},
     ISSN = 00483915,
     language = {English},
     year = 2001,
     publisher = {Blackwell Publishing},
     copyright = {Copyright ¿ 2001 Princeton University Press},
}

@Article{Zintzaras10,
  author = 	 {Zintzaras, Elias and Santos, Mauro and
                  Szathmary, Eors},
  title = 	 {Selfishness Versus Functional Cooperation in a Stochastic 
                  Protocell Model},
  journal = 	 {Journal of Theoretical Biolology},
  year = 	 2010,
  volume =	 267,
  pages =	 {605--613},
  annote =	 {How to design an evolvable artificial system capable to
   Increase in complexity? Although Darwin s theory of evolution by
   natural selection obviously offers a firm foundation little hope of
   success seems to be expected from the explanatory adequacy of
   modern evolutionary theory which does a good job at explaining what
   has already happened but remains practically helpless at predicting
   what will occur However the study of the major transitions in
   evolution clearly suggests that Increases in complexity have
   occurred on those occasions when the conflicting interests between
   competing individuals were partly subjugated This immediately
   raises the issue about levels of selection in evolutionary biology
   and the idea that multi-level selection scenarios are required for
   complexity to emerge After analyzing the dynamical behaviour of
   competing replicators within compartments we show here that a
   proliferation of differentiated catalysts and/or improvement of
   catalytic efficiency of ribozymes can potentially evolve in
   properly designed artificial cells where the strong internal
   competition between the different species of replicators is
   somewhat prevented (i e by choosing them with equal probability)
   Experimental evolution in these systems will likely stand as
   beautiful examples of artificial adaptive systems and will provide
   new insights to understand possible evolutionary paths to the
   evolution of metabolic complexity (C) 2010 Elsevier Ltd All rights
   reserved}
}

@Article{Boza10,
  author = 	 {Boza, Gergely and Szamado, Szabolcs},
  title = 	 {Beneficial Laggards: Multilevel Selection, 
                  Cooperative Polymorphism and
                  Division of Labour in {T}hreshold {P}ublic {G}ood {G}ames},
  journal = 	 {BMC Evol. Biol.},
  year = 	 2010,
  volume =	 10,
  pages =	 {Article~336},
  annote =	 {Background: The origin and stability of cooperation is
   a hot topic in social and behavioural sciences. A complicated
   conundrum exists as defectors have an advantage over cooperators,
   whenever cooperation is costly so consequently, not cooperating
   pays off. In addition, the discovery that humans and some animal
   populations, such as lions, are polymorphic, where cooperators and
   defectors stably live together - while defectors are not being
   punished-, is even more puzzling. Here we offer a novel explanation
   based on a Threshold Public Good Game (PGG) that includes the
   interaction of individual and group level selection, where
   individuals can contribute to multiple collective actions, in our
   model group hunting and group defense.  Results: Our results show
   that there are polymorphic equilibria in Threshold PGGs; that
   multi-level selection does not select for the most cooperators per
   group but selects those close to the optimum number of cooperators
   (in terms of the Threshold PGG). In particular for medium cost
   values division of labour evolves within the group with regard to
   the two types of cooperative actions (hunting
   vs. defense). Moreover we show evidence that spatial population
   structure promotes cooperation in multiple PGGs. We also
   demonstrate that these results apply for a wide range of non-linear
   benefit function types.  Conclusions: We demonstrate that
   cooperation can be stable in Threshold PGG, even when the
   proportion of so called free riders is high in the population. A
   fundamentally new mechanism is proposed how laggards, individuals
   that have a high tendency to defect during one specific group
   action can actually contribute to the fitness of the group, by
   playing part in an optimal resource allocation in Threshold Public
   Good Games. In general, our results show that acknowledging a
   multilevel selection process will open up novel explanations for
   collective actions.}
}

@Article{Rainey10,
  author = 	 {Rainey, Paul B. and  Kerr, Benjamin},
  title = 	 {Cheats as First Propagules: A New Hypothesis for the 
                  Evolution of Individuality During the Transition from 
                  Single Cells to Multicellularity},
  journal = 	 {Bioessays},
  year = 	 2010,
  volume =	 32,
  pages =	 {872--880},
  annote =	 {The emergence of individuality during the evolutionary
   transition from single cells to multicellularity poses a range of
   problems. A key issue is how variation in lower-level individuals
   generates a corporate (collective) entity with Darwinian
   characteristics. Of central importance to this process is the
   evolution of a means of collective reproduction, however, the
   evolution of a means of collective reproduction is not a trivial
   issue, requiring careful consideration of mechanistic
   details. Calling upon observations from experiments, we draw
   attention to proto-life cycles that emerge via unconventional
   routes and that transition, in single steps, individuality to
   higher levels. One such life cycle arises from conflicts among
   levels of selection and invokes cheats as a primitive germ line: it
   lays the foundation for collective reproduction, the basis of a
   self-policing system, the selective environment for the emergence
   of development, and hints at a plausible origin for a soma/germ
   line distinction.}  }


@Article{Pigliucci10,
  author = 	 {Pigliucci, Massimo},
  title = 	 {Okasha's Evolution and the Levels of Selection: 
                  Toward a Broader
                  Conception of Theoretical Biology},
  journal = 	 {Biol. Philos.},
  year = 	 2010,
  volume =	 25,
  pages =	 {405--415},
  annote =	 {The debate about the levels of selection has been one
   of the most controversial both in evolutionary biology and in
   philosophy of science.  Okasha's book makes the sort of
   contribution that simply will not be able to be ignored by anyone
   interested in this field for many years to come. However, my
   interest here is in highlighting some examples of how Okasha goes
   about discussing his material to suggest that his book is part of
   an increasingly interesting trend that sees scientists and
   philosophers coming together to build a broadened concept of
   "theory" through a combination of standard mathematical treatments
   and conceptual analyses. Given the often contentious history of the
   relationship between philosophy and science, such trend cannot but
   be welcome.}
}

@Article{Okasha09,
  author = 	 {Okasha, Samir},
  title = 	 {Individuals, Groups, Fitness and Utility: 
                  Multi-Level Selection Meets Social Choice Theory},
  journal = 	 {Biol. Philos.},
  year = 	 2009,
  volume =	 24,
  pages =	 {561--584},
  annote =	 {In models of multi-level selection, the property of
   Darwinian fitness is attributed to entities at more than one level
   of the biological hierarchy, e. g. individuals and groups. However,
   the relation between individual and group fitness is a
   controversial matter. Theorists disagree about whether group
   fitness should always, or ever, be defined as total (or average)
   individual fitness. This paper tries to shed light on the issue by
   drawing on work in social choice theory, and pursuing an analogy
   between fitness and utility. Social choice theorists have long been
   interested in the relation between individual and social utility,
   and have identified conditions under which social utility equals
   total (or average) individual utility. These ideas are used to shed
   light on the biological problem.}
}

@Article{Pigliucci09,
  author = 	 {Pigliucci, Massimo},
  title = 	 {{S}amir {O}kasha: {E}volution and the Levels of Selection},
  journal = 	 {Biol. Philos.},
  year = 	 2009,
  volume =	 24,
  pages =	 {551--560},
  annote =	 {The debate about the levels of selection has been one
   of the most controversial both in evolutionary biology and in
   philosophy of science.  Okasha's book makes the sort of
   contribution that simply will not be able to be ignored by anyone
   interested in this field for many years to come. However, my
   interest here is in highlighting some examples of how Okasha goes
   about discussing his material to suggest that his book is part of
   an increasingly interesting trend that sees scientists and
   philosophers coming together to build a broadened concept of
   "theory" through a combination of standard mathematical treatments
   and conceptual analyses. Given the often contentious history of the
   relationship between philosophy and science, such trend cannot but
   be welcome.}
}

@Article{Egas08,
  author = 	 {Egas, Martijn and Riedl, Arno},
  title = 	 {Proc. R. Soc. B.},
  journal = 	 {The Economics of Altruistic Punishment and the Maintenance 
                  of Cooperation},
  year = 	 2008,
  volume =	 275,
  pages =	 {871--878},
  annote =	 {Explaining the evolution and maintenance of cooperation
   among unrelated individuals is one of the fundamental problems in
   biology and the social sciences. Recent findings suggest that
   altruistic punishment is an important mechanism maintaining
   cooperation among humans. We experimentally explore the boundaries
   of altruistic punishment to maintain cooperation by varying both
   the cost and the impact of punishment, using an exceptionally
   extensive subject pool. Our results show that cooperation is only
   maintained if conditions for altruistic punishment are relatively
   favourable: low cost for the punisher and high impact on the
   punished. Our results indicate that punishment is strongly governed
   by its cost-to-impact ratio and that its effect on cooperation can
   be pinned down to one single variable: the threshold level of
   free-riding that goes unpunished. Additionally, actual pay-offs are
   the lowest when altruistic punishment maintains cooperation,
   because the pay-off destroyed through punishment exceeds the gains
   from increased cooperation. Our results are consistent with the
   interpretation that punishment decisions come from an amalgam of
   emotional response and cognitive cost-impact analysis and suggest
   that altruistic punishment alone can hardly maintain cooperation
   under multi-level natural selection. Uncovering the workings of
   altruistic punishment as has been done here is important because it
   helps predicting under which conditions altruistic punishment is
   expected to maintain cooperation.}
}

@Article{Helanterae06,
  author = 	 {Helanter{\"a}, H.},
  title = 	 {The Unity That Does Not Exist---A Review of 
                  {A.} {B}urt \& {R.} {T}rivers 2006: {G}enes in {C}onflict},
  journal = 	 {J. Evol. Bol.},
  year = 	 2006,
  volume =	 19,
  pages =	 {2067--2070},
  annote =	 {Organisms harbour several genetic elements with the
   potential to act selfishly, and thus undermine the fitness of the
   organism as a whole. In their book 'Genes in conflict', Austin Burt
   and Robert Trivers thoroughly review evolution and molecular
   biology of such selfish genetics elements, and set them in a kin
   selection framework. In this review I set their views in a larger
   multi-level selection framework, and consider potential problems in
   the study of selfish genetics elements.}
}

@Article{Okasha05,
  author = 	 {Okasha, Samir},
  title = 	 {Altruism, Group Selection and Correlated Interaction},
  journal = 	 {Brit. J. Phil. Sci.},
  year = 	 2005,
  volume =	 56,
  pages =	 {703--725},
  annote =	 {Group selection is one acknowledged mechanism for the
   evolution of altruism. It is well known that for altruism to spread
   by natural selection, interactions must be correlated; that is,
   altruists must tend to associate with one another. But does group
   selection itself require correlated interactions? Two possible
   arguments for answering this question affirmatively are
   explored. The first is a bad argument, for it rests on a
   product/process confusion. The second is a more subtle argument,
   whose validity (or otherwise) turns on issues concerning the
   meaning of multi-level selection and how it should be modelled. A
   cautious defence of the second argument is offered.
   1 Introduction
   2 Multi-level selection and the evolution of altruism
   3 Price's equation and multi-level selection
   4 Contextual analysis and multi-level selection
   5 The neighbour approach
   6 Recapitulation and conclusion.}
}

@Article{Okasha04,
  author = 	 {Okasha, Samir},
  title = 	 {Multi-Level Selection, Covariance and Contextual Analysis},
  journal = 	 {Brit. J. Phil. Sci.},
  year = 	 2004,
  volume =	 55,
  pages =	 {481--504},
  annote =	 {Two alternative statistical approaches to modelling
   multi-level selection in nature, both found in the contemporary
   biological literature, are contrasted. The simple covariance
   approach partitions the total selection differential on a
   phenotypic character into within-group and between-group
   components, and identifies the change due to group selection with
   the latter. The contextual approach partitions the total selection
   differential into different components, using multivariate
   regression analysis. The two approaches have different implications
   for the question of what constitutes group selection and what does
   not. I argue that the contextual approach is theoretically
   preferable. This has important implications for a number of issues
   in the philosophical debate about the levels of selection.}  }


@Article{Bowles04,
  author = 	 {Bowles, Samuel and  Gintis, Herbert},
  title = 	 {The Evolution of Strong Reciprocity: Cooperation 
                  in Heterogeneous Populations},
  journal = 	 {Theor. Population Biol.},
  year = 	 2004,
  volume =	 65,
  pages =	 {17--28},
  annote =	 {How do human groups maintain a high level of
   cooperation despite a low level of genetic relatedness among group
   members? We suggest that many humans have a predisposition to
   punish those who violate group-beneficial norms, even when this
   imposes a fitness cost on the punisher. Such altruistic punishment
   is widely observed to sustain high levels of cooperation in
   behavioral experiments and in natural settings.  We offer a model
   of cooperation and punishment that we call strong reciprocity:
   where members of a group benefit from mutual adherence to a social
   norm, strong reciprocators obey the norm and punish its violators,
   even though as a result they receive lower payoffs than other group
   members, such as selfish agents who violate the norm and do not
   punish, and pure cooperators who adhere to the norm but free-ride
   by never punishing. Our agent-based simulations show that, under
   assumptions approximating likely human environments over the
   100,000 years prior to the domestication of animals and plants, the
   proliferation of strong reciprocators when initially rare is highly
   likely, and that substantial frequencies of all three behavioral
   types can be sustained in a population. As a result, high levels of
   cooperation are sustained. Our results do not require that group
   members be related or that group extinctions occur. (C) 2003
   Published by Elsevier Inc.}  }


@Article{Gintis03,
  author = 	 {Gintis, Herbert},
  title = 	 {The Hitchhiker's Guide to Altruism: Gene-Culture 
                  Coevolution, and the Internalization of Norms},
  journal = 	 {J. Theor. Biol.},
  year = 	 2003,
  volume =	 220,
  pages =	 {407--418},
  annote =	 {An internal norm is a pattern of behavior enforced in
   part by internal sanctions, such as shame, guilt and loss of
   self-esteem, as opposed to purely external sanctions, such as
   material rewards and punishment. The ability to internalize norms
   is widespread among humans, although in some so-called
   "sociopaths", this capacity is diminished or lacking.  Suppose
   there is one genetic locus that controls the capacity to
   internalize norms. This model shows that if an internal norm is
   fitness enhancing, then for plausible patterns of socialization,
   the allele for internalization of norms is evolutionarily
   stable. This framework can be used to model Herbert Simon's (1990)
   explanation of altruism, showing that altruistic norms can
   "hitchhike" on the general tendency of internal norms to be
   personally fitness-enhancing. A multi-level selection, gene-culture
   coevolution argument then explains why individually
   fitness-reducing internal norms are likely to be prosocial as
   opposed to socially harmful. (C) 2003 Elsevier Science Ltd. All
   rights reserved.}  }

@Article{Kerr02,
  author = 	 {Kerr, Benjamin and Godfrey-Smith, Peter},
  title = 	 {Individualist and Multi-Level Perspectives on Selection 
                  in Structured Populations},
  journal = 	 {Biol. Philos.},
  year = 	 2002,
  volume =	 17,
  pages =	 {477--517},
  annote =	 {Recent years have seen a renewed debate over the
   importance of group selection, especially as it relates to the
   evolution of altruism. One feature of this debate has been
   disagreement over which kinds of processes should be described in
   terms of selection at multiple levels, within and between
   groups. Adapting some earlier discussions, we present a
   mathematical framework that can be used to explore the exact
   relationships between evolutionary models that do, and those that
   do not, explicitly recognize biological groups as fitness-bearing
   entities.  We show a fundamental set of mathematical equivalences
   between these two kinds of models, one of which applies a form of
   multi-level selection theory and the other being a form of
   "individualism." However, we also argue that each type of model can
   have heuristic advantages over the other. Indeed, it can be
   positively useful to engage in a kind of back-and-forth switching
   between two different perspectives on the evolutionary role of
   groups. So the position we defend is a "gestalt-switching
   pluralism".}  }


@Article{Kerr02a,
  author = 	 {Kerr, Benjamin and Godfrey-Smith, Peter},
  title = 	 {On {P}rice's Equation and Average Fitness},
  journal = 	 {Biol. Philos.},
  year = 	 2002,
  volume =	 17,
  pages =	 {551--565},
  annote =	 {A number of recent discussions have argued that George
   Price's equation for representing evolutionary change is a powerful
   and illuminating tool, especially in the context of debates about
   multiple levels of selection. Our paper dissects Price's equation
   in detail, and compares it to another statistical tool: the
   calculation and comparison of average fitnesses. The relations
   between Price's equation and equations for evolutionary change
   using average fitness are closer than is sometimes supposed. The
   two approaches achieve a similar kind of statistical summary of one
   generation of change, and they achieve this via a similar loss of
   information about the underlying fitness structure.}
}

@Article{Nachtomy02,
  author = 	 {Nachtomy, Ohad and   Shavit, Ayelet and Smith, Justin},
  title = 	 {Leibnizian Organisms, Nested Individuals, and 
                  Units of Selection},
  journal = 	 {Theory Biosci.},
  year = 	 2002,
  volume =	 121,
  pages =	 {205--230},
  annote =	 {Leibniz developed a new notion of individuality,
   according to which individuals are nested one within another,
   thereby abandoning the Aristotelian formula at the heart of
   substantialist metaphysics, 'one body, one substance'. On this
   model, the level of individuality is determined by the degree of
   activity, and partly defined by its relations with other
   individuals. In this article, we show the importance of this new
   notion of individuality for some persisting questions in
   theoretical biology. Many evolutionary theorists presuppose a model
   of individuality that will eventually reduce to spatiotemporal
   mechanisms, and some still look for an exclusive level or function
   to determine a unit of selection. In recent years, a number of
   alternatives to these exclusive approaches have emereged, and no
   consensus can be foreseen. It is for this reason that we propose
   the model of nested individuals. This model supports pluralistic
   multi-level selection and rejects an exclusive level or function
   for a unit of selection. Since activity is essential to the unity
   of an individual, this model focuses on integrating processes of
   interaction and replication instead of choosing between them. In
   addition, the model of nested individuals may also be seen as a
   distinct perspective among the various alternative models for the
   unit of selection. This model stresses activity and pluralism: it
   accepts simultaneuous co-existence of individuals at different
   levels, nested one within the other. Our aim in this article is to
   show now a chapter of the history of metaphysics may be fruitfully
   brought to bear on the current debate over the unit of selection in
   evolutionary biology.}  }

@Article{Canals98,
  author = 	 {Canals, Jos{\'e} and Vega-Redondo, Fernando},
  title = 	 {Multi-Level Evolution in Population Games},
  journal = 	 {Int. J. Game Theory},
  year = 	 1998,
  volume =	 27,
  pages =	 {21--35},
  annote =	 {In this paper, we analyze a generalization of the
   evolutionary model of Kandori, Mailath, & Rob (1993) where the
   population is partitioned into groups and evolution takes place "in
   parallel" at the following two levels: (i) within groups, at the
   lower level; among groups, at the higher one. Unlike in their
   context, efficiency considerations always overcome those of
   risk-dominance in the process of selecting the long-run
   equilibrium. This provides an explicitly dynamic basis for a
   conclusion reminiscent of those put forward in the biological
   literature by the so-called theories group selection. From a
   normative viewpoint, it suggests the potential importance of
   "decentralization", here understood as local and independent
   interaction.}  }

@Article{Simon10,
  author = 	 {Simon, Burton},
  title = 	 {A Dynamical Model of Two-Level Selection},
  journal = 	 {Evol. Ecol. Res.},
  year = 	 2010,
  volume =	 12,
  pages =	 {555--588},
  annote =	 {Question: How do continuous-time evolutionary 
   trajectories of two-level
   selection behave?
   Approach: Construct and solve a dynamical model of two-level selection
   capable of predicting evolutionary trajectories and equilibrium
   configurations.
   Mathematical methods: Evolutionary birth-death processes, simulation,
   large population asymptotics, numerical solutions of hyperbolic PDEs.
   Key assumptions: Environment composed of distinct groups of individuals.
   Individuals' birth and death rates are differentiable functions of the
   state of the environment. Groups' fissioning and extinction rates are
   integrable functions of the state of the environment.
   Main results: A continuous-time, discrete-state, stochastic model of
   two-level selection that can be simulated exactly. A continuous-time,
   continuous-state, deterministic (PDE) model of two-level selection that
   can be solved numerically. A mathematical connection between the
   stochastic and deterministic models. Equilibrium configurations of the
   environment in models of the evolution of cooperation by two-level
   selection often consist of complicated mixtures of groups of varying
   sizes, ages, and levels of cooperation.}
}

@Article{Goodnight11,
  author = 	 {Goodnight, Charles J.},
  title = 	 {Evolution in Metacommunities},
  journal = 	 {Phil. Trans. R. Soc. B},
  year = 	 2011,
  volume =	 366,
  pages =	 {1401--1409},
  annote =	 {A metacommunity can be defined as a set of communities
   that are linked by migration, and extinction and recolonization. In
   metacommunities, evolution can occur not only by processes that
   occur within communities such as drift and individual selection,
   but also by among-community processes, such as divergent selection
   owing to random differences among communities in species
   composition, and group and community-level selection. The effect of
   these among-community-level processes depends on the pattern of
   migration among communities. Migrating units may be individuals
   (migrant pool model), groups of individuals (single-species
   propagule pool model) or multi-species associations (multi-species
   propagule pool model). The most interesting case is the
   multi-species propagule pool model. Although this pattern of
   migration may a priori seem rare, it becomes more plausible in
   small well-defined 'communities' such as symbiotic associations
   between two or a few species. Theoretical models and experimental
   studies show that community selection is potentially an effective
   evolutionary force. Such evolution can occur either through genetic
   changes within species or through changes in the species
   composition of the communities. Although laboratory studies show
   that community selection can be important, little is known about
   how important it is in natural populations.}  }

@Article{Nunney85a,
  author = 	 {Len Nunney},
  title = 	 {Group Selection, Altruism, and Structured-Deme Models},
  journal = 	 {American Naturalist},
  year = 	 1985,
  volume =	 126,
  pages =	 {212--230}
}


@Article{Nunney85b,
  author = 	 {Len Nunney},
  title = 	 {Female-Biased Sex Ratios: Individual or Group Selection?},
  journal = 	 {Evolution},
  year = 	 1985,
  volume =	 39,
  pages =	 {349--361}
}

@Article{Lion11,
  author = 	 {S{\'e}bastien Lion and Vincent A. A. Jansen and Troy Day},
  title = 	 {Evolution in Structured Populations:
                  Beyond the Kin Versus Group Debate},
  journal = 	 {Trends Ecol. Evol.},
  year = 	 2011,
  volume =	 26,
  pages =	 {193--201},
  annote =	 {Much of the literature on social evolution is pervaded
by the old debate about the relative merits of kin and group
selection. In this debate, the biological interpretation of processes
occurring in real populations is often conflated with the mathematical
methodology used to describe these processes. Here, we highlight the
distinction between the two by placing this discussion within the
broader context of evolution in structured populations. In this review
we show that the current debate overlooks important aspects of the
interplay between genetic and demographic structuring, and argue that
a continued focus on the relative merits of kin versus group selection
distracts attention from moving the field forward.}  }

@Article{Leigh09,
  author = 	 {Leigh, E. G., Jr.},
  title = 	 {The Group Selection Controversy},
  journal = 	 {J. Evol. Biol.},
  year = 	 2009,
  volume =	 23,
  pages =	 {6--19},
  annote =	 {Many thought Darwinian natural selection could not
explain altruism. This error led Wynne-Edwards to explain sustainable
exploitation in animals by selection against overexploiting
groups. Williams riposted that selection among groups rarely overrides
within-group selection. Hamilton showed that altruism can evolve
through kin selection. How strongly does group selection influence
evolution? Following Price, Hamilton showed how levels of selection
interact: group selection prevails if Hamilton's rule applies. Several
showed that group selection drove some major evolutionary
transitions. Following Hamilton's lead, Queller extended Hamilton's
rule, replacing genealogical relatedness by the regression on an
actor's genotypic altruism of interacting neighbours' phenotypic
altruism. Price's theorem shows the generality of Hamilton's rule. All
instances of group selection can be viewed as increasing inclusive
fitness of autosomal genomes. Nonetheless, to grasp fully how
cooperation and altruism evolve, most biologists need more concrete
concepts like kin selection, group selection and selection among
individuals for their common good.  } }

@Article{Platt09,
  author = 	 {Thomas G. Platt and James D. Bever},
  title = 	 {Kin Competition and the Evolution
                  of Cooperation},
  journal = 	 {Trends Ecol. Evol.},
  year = 	 2009,
  volume =	 24,
  pages =	 {370--377},
  annote =	 {Kin and multilevel selection theories predict that
genetic structure is required for the evolution of
cooperation. However, local competition among relatives can limit
cooperative benefits, antagonizing the evolution of cooperation. We
show that several ecological factors determine the extent to which kin
competition constrains cooperative benefits. In addition, we argue
that cooperative acts that expand local carrying capacity are less
constrained by kin competition than other cooperative traits, and are
therefore more likely to evolve. These arguments are particularly
relevant to microbial cooperation, which often involves the production
of public goods that promote population expansion. The challenge now
is to understand how an organism's ecology influences how much
cooperative groups contribute to future generations and thereby the
evolution of cooperation.}  }

@Article{Rankin07,
  author = 	 {Daniel J. Rankin and Katja Bargum and Hanna Kokko},
  title = 	 {The Tragedy of the Commons in
                  Evolutionary Biology},
  journal = 	 {Trends Ecol. Evol.},
  year = 	 2007,
  volume =	 22,
  pages =	 {643--651},
  annote =	 {Garrett Hardin's tragedy of the commons is an analogy
that shows how individuals driven by self-interest can end up
destroying the resource upon which they all depend. The proposed
solutions for humans rely on highly advanced skills such as
negotiation, which raises the question of how non-human organisms
manage to resolve similar tragedies. In recent years, this question
has promoted evolutionary biologists to apply the tragedy of the
commons to a wide range of biological systems. Here, we provide tools
to categorize different types of tragedy and review different
mechanisms, including kinship, policing and diminishing returns that
can resolve conflicts that could otherwise end in tragedy. A central
open question, however, is how often biological systems are able to
resolve these scenarios rather than drive themselves extinct through
individual-level selection favouring self-interested behaviours.}  }

@Article{Taylor07:Dilemma,
  author = 	 {Christine Taylor and Martin A. Nowak},
  title = 	 {Transforming the Dilemma},
  journal = 	 {Evolution},
  year = 	 2007,
  volume =	 61,
  pages =	 {2281--2292},
  annote =	 {How does natural selection lead to cooperation between
competing individuals ? The Prisoner's Dilemma captures the essence of
this problem. Two players can either cooperate or defect. The payoff
for mutual cooperation, R, is greater than the payoff for mutual
defection, P. But a defector versus a cooperator receives the highest
payoff, T, where as the cooperator obtains the lowest payoff,
S. Hence, the Prisoner's Dilemma is defined by the payoff ranking T >
R > P > S. In a well-mixed population, defectors always have a higher
expected payoff than cooperators, and therefore natural selection
favors defectors. The evolution of cooperation requires specific
mechanisms. Here we discuss five mechanisms for the evolution of
cooperation: direct reciprocity, indirect reciprocity, kin selection,
group selection, and network reciprocity (or graph selection). Each
mechanism leads to a transformation of the Prisoner's Dilemma payoff
matrix. From the transformed matrices, we derive the fundamental
conditions for the evolution of cooperation. The transformed matrices
can be used in standard frameworks of evolutionary dynamics such as
the replicator equation or stochastic processes of game dynamics in
finite populations.}  }

@Article{West07,
  author = 	 {Stuart A. West and Stephen P. Diggle and Angus Buckling
                  and Andy Gardner and Ashleigh S. Griffin},
  title = 	 {The Social Lives of Microbes},
  journal = 	 {Ann. Rev. Evol. Ecol. Systematics},
  year = 	 2007,
  volume =	 38,
  pages =	 {53--77},
  annote = {Our understanding of the social lives of microbes has been
  revolutionized over the past 20 years. It used to be assumed that
  bacteria and other microorganisms lived relatively independent
  unicellular lives, without the cooperative behaviors that have
  provoked so much interest in mammals, birds, and insects. However, a
  rapidly expanding body of research has completely overturned this
  idea, showing that microbes indulge in a variety of social behaviors
  involving complex systems of cooperation, communication, and
  synchronization. Work in this area has already provided some elegant
  experimental tests of social evolutionary theory, demonstrating the
  importance of factors such as relatedness, kin discrimination,
  competition between relatives, and enforcement of cooperation. Our
  aim here is to review these social behaviors, emphasizing the unique
  opportunities they offer for testing existing evolutionary theory as
  well as highlighting the novel theoretical problems that they pose.}
}

@Article{Lehmann06,
  author = 	 {L. Lehmann and L. Keller},
  title = 	 {The Evolution of Cooperation and Altruism---A 
                  General Framework and a Classification of Models},
  journal = 	 {J. Evol. Biol.},
  year = 	 2006,
  volume =	 19,
  pages =	 {1365--1376},
  annote =	 {One of the enduring puzzles in biology and the social
sciences is the origin and persistence of intraspecific cooperation
and altruism in humans and other species. Hundreds of theoretical
models have been proposed and there is much confusion about the
relationship between these models. To clarify the situation, we
developed a synthetic conceptual framework that delineates the
conditions necessary for the evolution of altruism and cooperation. We
show that at least one of the four following conditions needs to be
fulfilled: direct benefits to the focal individual performing a
cooperative act; direct or indirect information allowing a better than
random guess about whether a given individual will behave
cooperatively in repeated reciprocal interactions; preferential
interactions between related individuals; and genetic correlation
between genes coding for altruism and phenotypic traits that can be
identified. When one or more of these conditions are met, altruism or
cooperation can evolve if the cost-to-benefit ratio of altruistic and
cooperative acts is greater than a threshold value. The
cost-to-benefit ratio can be altered by coercion, punishment and
policing which therefore act as mechanisms facilitating the evolution
of altruism and cooperation. All the models proposed so far are
explicitly or implicitly built on these general principles, allowing
us to classify them into four general categories.}  }

@Article{Wilson83,
  author = 	 {David Sloan Wilson},
  title = 	 {The Group Selection Controversy: History and
                  Current Status},
  journal = 	 {Ann. Rev. Ecol. Systematics},
  year = 	 1983,
  volume =	 14,
  pages =	 {159--187}
}

@Article{West07a,
  author = 	 {S. A. West and A. S. Griffin and A. Gardner},
  title = 	 {Social Semantics: Altruism, Cooperation, Mutualism, 
                  Strong Reciprocity and Group Selection},
  journal = 	 {J. Evol. Biol.},
  year = 	 2007,
  volume =	 20,
  pages =	 {415--432},
  annote =	 {From an evolutionary perspective, social behaviours are
those which have fitness consequences for both the individual that
performs the behaviour, and another individual. Over the last 43
years, a huge theoretical and empirical literature has developed on
this topic. However, progress is often hindered by poor communication
between scientists, with different people using the same term to mean
different things, or different terms to mean the same thing. This can
obscure what is biologically important, and what is not. The potential
for such semantic confusion is greatest with interdisciplinary
research. Our aim here is to address issues of semantic confusion that
have arisen with research on the problem of cooperation. In
particular, we: (i) discuss confusion over the terms kin selection,
mutualism, mutual benefit, cooperation, altruism, reciprocal altruism,
weak altruism, altruistic punishment, strong reciprocity, group
selection and direct fitness; (ii) emphasize the need to distinguish
between proximate (mechanism) and ultimate (survival value)
explanations of behaviours. We draw examples from all areas, but
especially recent work on humans and microbes.  } }

@Article{Wilson08,
  author = 	 {D. S. Wilson},
  title = 	 {Social Semantics: Toward a Genuine Pluralism in the 
                  Study of Social Behaviour},
  journal = 	 {J. Evol. Biol.},
  year = 	 2008,
  volume =	 21,
  pages =	 {368--373},
  annote =	 {Pluralism is the coexistence of equivalent theoretical
frameworks, either because they are historically entrenched or because
they achieve separate insights by viewing the same process in
different ways. A recent article by West et al. [Journal of
Evolutionary Biology (2007) vol. 20, 415-432] attempts to classify the
many equivalent frameworks that have been developed to study the
evolution of social behaviour. This article addresses shortcomings in
the West et al.'s article, especially with respect to multilevel
selection, in a common effort to maximize the benefits of pluralism
while minimizing the semantic costs.}  }

@Article{West08,
  author = 	 {S. A. West and A. S. Griffin and A. Gardner},
  title = 	 {Social Semantics: How Useful Has Group Selection Been?},
  journal = 	 {J. Evol. Biol.},
  year = 	 2008,
  volume =	 21,
  pages =	 {374--385},
  annote =	 {In our social semantics review ( J. Evol. Biol., 2007,
415-432), we discussed some of the misconceptions and sources of
confusion associated with group selection. Wilson (2007, this issue)
claims that we made three errors regarding group selection. Here, we
aim to expand upon the relevant points from our review in order to
refute this claim. The last 45 years of research provide clear
evidence of the relative use of the kin and group selection
approaches. Kin selection methodologies are more tractable, allowing
the construction of models that can be applied more easily to specific
biological examples, including those chosen by Wilson to illustrate
the utility of the group selection approach. In contrast, the group
selection approach is not only less useful, but also appears to
frequently have negative consequences by fostering confusion that
leads to wasted effort. More generally, kin selection theory allows
the construction of a unified conceptual overview that can be applied
across all taxa, whereas there is no formal theory of group
selection.}  }

@Article{Hamilton64a,
  author = 	 {Hamilton, W. D.},
  title = 	 {The Genetical Evolution of Social Behavior. {I}},
  journal = 	 {J. Theor. Biol.},
  year = 	 1964,
  volume =	 7,
  pages =	 {1--16}
}

@Article{Hamilton64b,
  author = 	 {Hamilton, W. D.},
  title = 	 {The Genetical Evolution of Social Behavior. {II}},
  journal = 	 {J. Theor. Biol.},
  year = 	 1964,
  volume =	 7,
  pages =	 {17--52}
}


@Article{Lion09,
  author = 	 {S. Lion and S. Gandon},
  title = 	 {Habitat Saturation and the Spatial Evolutionary Ecology
                  of Altruism},
  journal = 	 {J. Evol. Biol.},
  year = 	 2009,
  volume =	 22,
  pages =	 {1487--1502},
  annote =	 {Under which ecological conditions should individuals
help their neighbours? We investigate the effect of habitat saturation
on the evolution of helping behaviours in a spatially structured
population. We combine the formalisms of population genetics and
spatial moment equations to tease out the effects of various
physiological (direct benefits and costs of helping) and ecological
parameters (such as the density of empty sites) on the selection
gradient on helping. Our analysis highlights the crucial importance of
demography for the evolution of helping behaviours. It shows that
habitat saturation can have contrasting effects, depending on the form
of competition (direct vs. indirect competition) and on the
conditionality of helping. In our attempt to bridge the gap between
spatial ecology and population genetics, we derive an expression for
relatedness that takes into account both habitat saturation and the
spatial structure of genetic variation. This analysis helps clarify
discrepancies in the results obtained by previous theoretical
studies. It also provides a theoretical framework taking into account
the interplay between demography and kin selection, in which new
biological questions can be explored.}  }

@Article{Wilson77,
  author = 	 {David Sloan Wilson},
  title = 	 {Structured Demes and the Evolution of 
                  Group-Advantageous Traits},
  journal = 	 {American Naturalist},
  year = 	 1977,
  volume =	 111,
  pages =	 {157--185},
  annote =	 {1. Most organisms interact with a set of neighbors
smaller than the deme (its trait group). Demes therefore are not only
a population of individuals but also a population of groups
(structured demes). 2. Trait groups vary in their composition. The
minimum variance to be expected is that arising from a binomial
distribution. Most populations have a higher variance than this due to
(a) differential interactions with the environment and (b) the effects
of reproduction inside the trait groups. 3. As a consequence of this
variation, an individual on the average experiences its own "type" in
a greater frequency than actually exists in the deme. Its behaviors
are therefore directed differentially toward fellow types, and this is
the fundamental requirement for the evolution of altruism. 4. Models
are presented for warning cries and other donor-recipient relations,
resource notification, the evolution of prudence in exploitation and
interference competition, and the effect of differential trait-group
extinction. In all cases evolution in structured demes differs from
traditional individual-selection models. Individual selection
corresponds to the case where there is zero variance among trait
groups, that is, complete homogeneity. 5. The "threshold" variance
permitting the evolution of altruism (negative fitness change to the
donor) is that arising from a binomial distribution. As this is the
minimum to be expected in nature, this theory predicts that at least
weakly altruistic behavior should be a common occurrence (but see
[9]). 6. If a population is overexploiting its resource, a decrease in
feeding rate through interference may be selected for given any
trait-group variation. 7. When trait groups are composed entirely of
siblings (i.e., kin groups), the model is mathematically equivalent to
kin selection. 8. As well as increasing population fitness, social
systems may also evolve an "immunity" against group-detrimental
types. 9. If a given group-advantageous effect can be accomplished
through both altruistic and selfish mechanisms, the selfish mechanism
will be selected. A paucity of altruistic behaviors may signify that
it is usually possible to create the same result selfishly--not that
altruism "cannot" be selected for} }

@Article{Fletcher09,
  author = 	 {Jeffrey A. Fletcher and Michael Doebeli},
  title = 	 {A Simple and General Explanation for the 
                  Evolution of Altruism},
  journal = 	 {Proc. Roy. Soc. B},
  year = 	 2009,
  volume =	 276,
  pages =	 {13--19},
  annote =	 {We present a simple framework that highlights the most
fundamental requirement for the evolution of altruism: assortment
between individuals carrying the cooperative genotype and the helping
behaviours of others with which these individuals interact. We
partition the fitness effects on individuals into those due to self
and those due to the \u2018interaction environment\u2019, and show
that it is the latter that is most fundamental to understanding the
evolution of altruism. We illustrate that while kinship or genetic
similarity among those interacting may generate a favourable structure
of interaction environments, it is not a fundamental requirement for
the evolution of altruism, and even suicidal aid can theoretically
evolve without help ever being exchanged among genetically similar
individuals. Using our simple framework, we also clarify a common
confusion made in the literature between alternative fitness
accounting methods (which may equally apply to the same biological
circumstances) and unique causal mechanisms for creating the
assortment necessary for altruism to be favoured by natural
selection.}  }

@Article{Lion09a,
  author = 	 {S{\'e}bastien Lion},
  title = 	 {Relatedness in Spatially Structured Populations 
                  with Empty Sites: An Approach Based on Spatial Moment 
                  Equations},
  journal = 	 {J. Theor. Biol.},
  year = 	 2009,
  volume =	 260,
  pages =	 {121--131},
  annote =	 {Taking into account the interplay between spatial
ecological dynamics and selection is a major challenge in evolutionary
ecology. Although inclusive fitness theory has proven to be a very
useful tool to unravel the interactions between spatial genetic
structuring and selection, applications of the theory usually rely on
simplifying demographic assumptions. In this paper, I attempt to
bridge the gap between spatial demographic models and kin selection
models by providing a method to compute approximations for relatedness
coefficients in a spatial model with empty sites. Using spatial moment
equations, I provide an approximation of nearest-neighbour relatedness
on random regular networks, and show that this approximation performs
much better than the ordinary pair approximation. I discuss the
connection between the relatedness coefficients I define and those
used in population genetics, and sketch some potential extensions of
the theory.}  }

@article{Hirose22072011,
author = {Hirose, Shigenori and Benabentos, Rocio and Ho, Hsing-I and Kuspa, Adam and Shaulsky, Gad}, 
title = {Self-Recognition in Social Amoebae Is Mediated by Allelic Pairs of Tiger Genes}, 
volume = 333, 
number = 6041, 
pages = {467-470}, 
year = 2011, 
journal = {Science},
doi = {10.1126/science.1203903}, 
abstract ={Free-living cells of the social amoebae Dictyostelium
discoideum can aggregate and develop into multicellular fruiting
bodies in which many die altruistically as they become stalk cells
that support the surviving spores. Dictyostelium cells exhibit kin
discriminationâ€”a potential defense against cheaters, which
sporulate without contributing to the stalk. Kin discrimination
depends on strain relatedness, and the polymorphic genes tgrB1 and
tgrC1 are potential components of that mechanism. Here, we demonstrate
a direct role for these genes in kin discrimination. We show that a
matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient
for attractive self-recognition, which is mediated by differential
cell-cell adhesion. We propose that TgrB1 and TgrC1 proteins mediate
this adhesion through direct binding. This system is a genetically
tractable ancient model of eukaryotic self-recognition.},  
}

@Article{Leadbeater11,
  author = 	 {Ellouise Leadbeater b*mand Jonathan M. Carruthers 
                  and Jonathan P. Green and Neil S. Rosser 
                  and Jeremy Field},
  title = 	 {Nest Inheritance Is the Missing Source of Direct 
                  Fitness in a Primitively Eusocial Insect},
  journal = 	 {Science},
  year = 	 2011,
  volume =	 333,
  number =	 6044,
  pages =	 {874--876},
  abstract= {Animals that cooperate with nonrelatives represent a
challenge to inclusive fitness theory, unless cooperative behavior is
shown to provide direct fitness benefits. Inheritance of breeding
resources could provide such benefits, but this route to cooperation
has been little investigated in the social insects. We show that nest
inheritance can explain the presence of unrelated helpers in a classic
social insect model, the primitively eusocial wasp Polistes
dominulus. We found that subordinate helpers produced more direct
offspring than lone breeders, some while still subordinate but most
after inheriting the dominant position. Thus, while indirect fitness
obtained through helping relatives has been the dominant paradigm for
understanding eusociality in insects, direct fitness is vital to
explain cooperation in P. dominulus.}  }

@Article{Kiers11,
  author = 	 {E. Toby Kiers and Marie Duhamel and Yugandhar Beesetty
                  and Jerry A. Mensah and Oscar Franken and Erik Verbruggen
                  and Carl R. Fellbaum and George A. Kowalchuk 
                  and Miranda M. Hart and Alberto Bago and Todd M. Palmer
                  and Stuart A. West and Philippe Vandenkoornhuyse
                  and Jan Jansa and Heike B\"ucking},
  title = 	 {Reciprocal Rewards Stabilize Cooperation in the 
                  Mycorrhizal Symbiosis},
  journal = 	 {Science},
  year = 	 2011,
  volume =	 333,
  number =	 6044,
  pages =	 {880--882},
  annote =	 {Plants and their arbuscular mycorrhizal fungal
symbionts interact in complex underground networks involving multiple
partners. This increases the potential for exploitation and defection
by individuals, raising the question of how partners maintain a fair,
two-way transfer of resources. We manipulated cooperation in plants
and fungal partners to show that plants can detect, discriminate, and
reward the best fungal partners with more carbohydrates. In turn,
their fungal partners enforce cooperation by increasing nutrient
transfer only to those roots providing more carbohydrates. On the
basis of these observations we conclude that, unlike many other
mutualisms, the symbiont cannot be \u201censlaved.\u201d Rather, the
mutualism is evolutionarily stable because control is bidirectional,
and partners offering the best rate of exchange are rewarded.}  }

@Article{Johnson11:Overconfidence,
  author = 	 {Johnson, Dominic D.P. and Fowler, James H.},
  title = 	 {The evolution of Overconfidence},
  journal = 	 {Nature},
  year = 	 2011,
  volume =	 477,
  number =	 7364,
  pages =	 {317--320},
  annote =	 {Confidence is an essential ingredient of success in a
wide range of domains ranging from job performance and mental health
to sports, business and combat1, 2, 3, 4. Some authors have suggested
that not just confidence but overconfidence\u2014believing you are
better than you are in reality\u2014is advantageous because it serves
to increase ambition, morale, resolve, persistence or the credibility
of bluffing, generating a self-fulfilling prophecy in which
exaggerated confidence actually increases the probability of success3,
4, 5, 6, 7, 8. However, overconfidence also leads to faulty
assessments, unrealistic expectations and hazardous decisions, so it
remains a puzzle how such a false belief could evolve or remain stable
in a population of competing strategies that include accurate,
unbiased beliefs. Here we present an evolutionary model showing that,
counterintuitively, overconfidence maximizes individual fitness and
populations tend to become overconfident, as long as benefits from
contested resources are sufficiently large compared with the cost of
competition. In contrast, unbiased strategies are only stable under
limited conditions. The fact that overconfident populations are
evolutionarily stable in a wide range of environments may help to
explain why overconfidence remains prevalent today, even if it
contributes to hubris, market bubbles, financial collapses, policy
failures, disasters and costly wars9, 10, 11, 12, 13.}  }

