[Paleopsych] SW: On Collective Action in Large Groups

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Evolution of Behavior: On Collective Action in Large Groups

    The following points are made by Ernst Fehr (Nature 2004 432:449):
    1) War is a prime example of large-scale within-group cooperation
    between genetically unrelated individuals. War also illustrates the
    fact that within-group cooperation often serves the purpose of
    between-group aggression. Modern states are able to enforce
    cooperation in large groups by means of sophisticated institutions
    that punish individuals who refuse to meet their duties and reward
    those who follow their superiors' commands. The existence of such
    cooperation-enhancing institutions is very puzzling from an
    evolutionary viewpoint, however, because no other species seems to
    have succeeded in establishing large-scale cooperation among
    genetically unrelated strangers(1).
    2) The puzzle behind this cooperation can be summarized as follows.
    Institutions that enhance within-group cooperation typically benefit
    all group members. The effect of a single group member on the
    institution's success is negligible, but the contribution cost is not
    negligible for the individual. Why, therefore, should a
    self-interested individual pay the cost of sustaining cooperative
    institutions? More generally, why should a self-interested individual
    contribute anything to a public good that -- once it exists -- an
    individual can consume regardless of whether he contributed or not?
    Recent work(2) advances the scope of reputation-based models(3-5) and
    demonstrates that individuals' concern for their reputation may be a
    solution to this puzzle.
    3) Evolutionary psychologists have sought to answer the puzzle of
    human collective action for decades. However, progress was limited
    because of a lack of commitment to mathematically rigorous theorizing.
    Many researchers erroneously thought that the notion of reciprocal
    altruism, formalized as a tit-for-tat strategy for two-person
    interactions, provides the solution to the problem. It was speculated
    that reciprocal altruism "may favor a multiparty altruistic system in
    which altruistic acts are dispensed freely among more than two
    individuals". However, it is always easier to speculate than to
    provide a rigorous model, and the speculation is likely to be wrong in
    this case.
    4) In the context of the problem of public-goods provision, a
    reciprocally altruistic individual is willing to contribute to the
    public good if sufficient numbers of other group members are also
    willing to contribute. Unfortunately, the presence of only a small
    number of defectors quickly causes cooperation to unravel if it is
    solely based on conditionally cooperative behavior, because the
    defectors induce the conditional cooperators to defect as well. Theory
    and simulations suggest that reciprocally altruistic strategies can
    only sustain high levels of cooperation in two-person interactions.
    Moreover, experimental evidence indicates that cooperation in
    public-good games typically unravels because it is not possible to
    discipline "free riders" -- those who take advantage of others'
    cooperation -- if only conditionally cooperative strategies are
    References (abridged):
    1. Fehr, E. & Fischbacher, U. Nature 425, 785-791 (2003)
    2. Panchanathan, K. & Boyd, R. Nature 432, 499-502 (2004)
    3. Nowak, M. A. & Sigmund, K. Nature 393, 573-577 (1998)
    4. Leimar, O. & Hammerstein, P. Proc. R. Soc. Lond. B 268, 745-753
    5. Gintis, H., Smith, E. A. & Bowles, S. J. Theor. Biol. 213, 103-119
    Nature http://www.nature.com/nature
    Related Material:
    Notes by ScienceWeek:
    In this context, the term "altruism" refers in general to behavior
    that benefits another individual, usually of the same species, at the
    expense of the agent. The phenomenon is widespread among various
    species, and has been interpreted by some as apparently at odds with
    Darwinian theory. Theories of altruism in biology are often concerned
    with "cost-benefit" analysis as dictated by the logic of natural
    The term "Hamilton's rule" refers to the prediction that genetically
    determined behavior that benefits another organism, but at some cost
    to the agent responsible, will spread by natural selection when the
    relation (rb-c} > 0 is satisfied, where (r) is the degree of
    relatedness between agent and recipient, (b) is the improvement of
    individual fitness of the recipient caused by the behavior, and (c) is
    the cost of the agent's individual fitness as a result of the
    behavior. The rule was first proposed by William D. Hamilton
    (1936-2000), and Hamilton's theory is often referred to as "kin
    selection". As an example: A mutation that affected the behavior of a
    sterile worker bee so that she fed her fertile queen but starved
    herself would increase the inclusive fitness of that worker because,
    while her own fitness decreased, her actions increased the fitness of
    a close relative.
    The following points are made by Mark Ridley (citation below):
    1) Natural selection working on groups of close genetic relatives is
    called kin selection. In species in which individuals sometimes meet
    one another, such as in social groups, individuals may be able to
    influence each other's reproduction. Biologists call a behavior
    pattern altruistic if it increases the number of offspring produced by
    the recipient and decreases that of the altruist. (Notice that the
    term in biology, unlike in human action, implies nothing about the
    altruist's intentions: it is a motive-free account of reproductive
    consequences.) Can natural selection ever favor altruistic actions
    that decrease the reproduction of the actor? If we take a strictly
    organismic view of natural selection, it would seem to be impossible.
    Yet, as a growing list of natural observations records, animals behave
    in an apparently altruistic manner. The altruism of the sterile
    'workers' in such insects as ants and bees is one undoubted example.
    In such cases, the altruism is extreme, as the workers do not
    reproduce in some species.
    2) Altruistic behavior often takes place between genetic relatives,
    where it is most likely explained by the theory of kin selection. Let
    us suppose for simplicity that we have two types of organism,
    altruistic and selfish. A hypothetical example might be that, when
    someone is drowning, an altruist would jump in and try and save him or
    her, whereas the selfish individual would not. The altruistic act
    decreases the altruist's chance of survival by some amount which we
    call c (for cost), because the altruist runs some risk of drowning.
    The action increases the chance of survival of the recipient by an
    amount b (for benefit). If the altruists dispensed their aid
    indiscriminately to other individuals, benefits will be received by
    other altruists and by selfish individuals in the same proportion as
    they exist in the population. Natural selection will then favor the
    selfish types, because they receive the benefits but do not pay the
    3) For altruism to evolve, it must be directed preferentially to other
    altruists. Suppose that acts of altruism were initially given only to
    other altruists. In such a case, what would be the condition for
    natural selection to favor altruism? The answer is that the altruism
    must take place only in circumstances in which the benefit to the
    recipient exceeds the cost to the altruist. This relation will hold
    true if the altruist is a better swimmer than the recipient, but it
    does not logically have to be true (if, for instance, the altruist
    were a poor swimmer and the recipients were capable of looking after
    themselves, the net result of the altruist's heroic plunge into the
    water might merely be that the altruist would drown). If the
    recipient's benefit exceeds the altruist's cost, then a net increase
    occurs in the average fitness of the altruistic types as a whole. This
    condition has only theoretical interest. In practice, it is usually
    (maybe always) impossible for altruism to be directed only to other
    altruists, because they cannot be recognized with certainty. It may be
    possible, however, for altruism to be directed at a class of
    individuals that contains a disproportionate number of altruists
    relative to their frequency in the population. For example, altruism
    may be directed toward genetic relatives. In this case, if a gene for
    altruism appears in an individual, it is also likely to be in its
    Adapted from: Mark Ridley: Evolution. 2nd Edition. Blackwell Science
    1996, p.321.
    Related Material:
    The following points are made by Edward O. Wilson (citation below):
    1) Altruism is self-destructive behavior performed for the benefit of
    others. The use of the word altruism in biology has been faulted by
    Williams and Williams (1957), who suggest that the alternative
    expression "social donorism" is preferable because it has less
    gratuitous emotional flavor. Even so, altruism has been used as a term
    in connection with evolutionary argumentation by Haldane (1932) and
    rigorous genetic theory by Hamilton (1964), and it has the great
    advantage of being instantly familiar. The self-destruction can range
    in intensity all the way from total bodily sacrifice to a slight
    diminishment of reproductive powers. Altruistic behavior is of course
    commonplace in the responses of parents toward their young. It is far
    less frequent, and for our purposes much more interesting, when
    displayed by young toward their parents or by individuals toward
    siblings or other, more distantly related members of the same species.
    Altruism is a subject of importance in evolution theory because it
    implies the existence of group selection, and its extreme development
    in the social insects is therefore of more than ordinary interest. The
    great scope and variety of the phenomenon in the social insects is
    best indicated by citing a few concrete examples:
    a) The soldier caste of most species of termites and ants is virtually
    limited in function to colony defense. Soldiers are often slow to
    respond to stimuli that arouse the rest of the colony, but, when they
    do, they normally place themselves in the position of maximum danger.
    When nest walls of higher termites such as Nasutitermes are broken
    open, for example, the white, defenseless nymphs and workers rush
    inward toward the concealed depths of the nest, while the soldiers
    press outward and mill aggressively on the outside of the nest.
    Nutting (personal communication) witnessed soldiers of Amitermes
    emersoni in Arizona emerge from the nest well in advance of the
    nuptial flights, wander widely around the nest vicinity, and
    effectively tie up in combat all foraging ants that could have
    endangered the emerging winged reproductives.
    b) I have observed that injured workers of the fire ant Solenopsis
    saevissima leave the nest more readily and are more aggressive on the
    average than their uninjured sisters. Dying workers of the harvesting
    ant Pogonomyrmex badius tend to leave the nest altogether. Both
    effects may be no more than meaningless epiphenomena, but it is also
    likely that the responses are altruistic. To be specific, injured
    workers are useless for most functions other than defense, while dying
    workers pose a sanitary problem.
    c) Alarm communication, which is employed in one form or other
    throughout the higher social groups, has the effect of drawing workers
    toward sources of danger while protecting the queens, the brood, and
    the unmated sexual forms.
    d) Honeybee workers possess barbed stings that tend to remain embedded
    when the insects pull away from their victims, causing part of their
    viscera to be torn out and the bees to be fatally injured. A similar
    defensive maneuver occurs in many polybiine wasps, including Synoeca
    surinama and at least some species of Polybia and Stelopolybia and the
    ant Pogonomyrmex badius. The fearsome reputation of social bees and
    wasps in comparison with other insects is due to their general
    readiness to throw their lives away upon slight provocation.
    e) When fed exclusively on sugar water, honeybee workers can still
    raise larvae -- but only by metabolizing and donating their own tissue
    proteins. That this donation to their sisters actually shortens their
    own lives is indicated by the finding of de Groot (1953) that
    longevity in workers is a function of protein intake.
    f) Female workers of most social insects curtail their own egg laying
    in the presence of a queen, either through submissive behavior or
    through biochemical inhibition. The workers of many ant and stingless
    bee species lay special trophic eggs that are fed principally to the
    larvae and queen.
    g) The "communal stomach", or distensible crop, together with a
    specially modified proventriculus, forms a complex storage and pumping
    system that functions in the exchange of liquid food among members of
    the same colony in the higher ants. In both honeybees and ants, newly
    fed workers often press offerings of ingluvial food on nestmates
    without being begged, and they may go so far as to expend their supply
    to a level below the colony average.
    2) These diverse physiological and behavioral responses are difficult
    to interpret in any way except as altruistic adaptations that have
    evolved through the agency of natural selection operating at the
    colony level. The list by no means exhausts the phenomena that could
    be placed in the same category.
    Adapted from: Edward O. Wilson: The Insect Societies. Harvard
    University Press 1971, p.321.

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