Turkey, cooperation and serotonin

Tryptophan is a chemical precursor to serotonin that can be found in turkey. A recent study suggest that it could reduce cooperation in prisoner's dilemma:

half of the volunteers were given a drink that depleted their tryptophan levels prior to the start of the game, thereby decreasing serotonin levels in their brain. Rogers and his team found that dampening serotonin activity significantly decreased the level of cooperation among the players, and that this group also rated fellow players as less trustworthy. "The findings suggest that a serotonin deficit might impair sustained cooperation," says Rogers.[technologyreview]

Evolution, cooperation and kinds of altruism

[Another clarification attempt; as ususal, comments welcome!]

Perhaps the most remarkable aspect of evolution is its ability to generate cooperation in a competitive world. Thus, we might add "natural cooperation" as a third fundamental principle of evolution beside mutation and natural selection (Nowak, 2006, p. 1563)

In a first approximation, a cooperative behavior i) benefits the recipient and ii) is beneficent or costly to the actor. Thus cooperation has two components: altruism (costly,) and mutual benefits (beneficent).

Following Sober and Wilson (1998), one may distinguishes evolutionary (or biological) altruism from psychological altruism. Psychological altruism is a psychological motivation that take another agent’s well-being (or utility) as a ultimate ends, i.e., the other agent’s well-being is “is desired for its own sake, rather than because the agent thinks that satisfying the desire will lead to the satisfaction of some other desire” (Stich, 2007, p. 268). Evolutionary altruism refers to behavior by which an organism engages in a costly behavior that benefits another organism, the cost and benefits being evaluated in terms of fitness consequences. Biologists, since Darwin, wondered why an individual would invest time and resources to help another: “He who was ready to sacrifice his life, […] rather than betray his comrades, would often leave no offspring to inherit his noble nature” (Darwin, 1871/2000, p. 130). They came up with two types of explanation: cooperation has either direct or indirect fitness consequences.

As demonstrated by Grafen, population genetics entails that natural selection favors individuals that maximize their fitness (Grafen, 1999, 2002, 2006). It does not mean that biological agents are optimal or perfect, but rather that they optimize their fitness: they tend to behave in such a way that their genes get replicated. This tendency is statistical, not teleological: on average, they do better than chance. For at least three situations (There are others, but I will discuss only the most salient in the literature), gene propagation and fitness optimization may be facilitated by others organisms and requires cooperation.

Fig. 1, based on West et al, 2007.

Cooperation can have direct or indirect fitness benefit, i.e., cooperating can contribute to one’s own survival and reproduction (direct) or it can contrbute to genetically related organisms’ survival and reproduction (indirect). Since relatives share genes with the actor, helping them is a way to maximize indirect fitness (Hamilton, 1964a, 1964b). Cooperative individuals can also maximize direct fitness if they reciprocate in repeated encounters (Trivers, 1971). A’s helping B is fitness-enhancing if A can expect B to help him in the future (direct reciprocity, or “tit-for-tat” altruism (Axelrod, 1984)). Indirect reciprocity brings a third individual: A helps B even if A never encountered B in the past because helping B contribute to building a good reputation and may result in being helped by another individual C (Nowak & Sigmund, 2005). Cooperative individuals are thus more likely to be helped (see Fig.2).

From Nowak (2006)

Direct reciprocity can be compared to “a barter economy based on the immediate exchange of goods, whereas indirect reciprocity resembles the invention of money. The money that fuels the engines of indirect reciprocity is reputation. (Nowak, 2006, p. 1561)”. Indirect reciprocity also explains evolutionary altruism as costly signaling (Zahavi & Zahavi, 1997). Evolutionarily speaking, the peacock’s tail is not the most useful body part: it makes movement difficult and is far from being discreet. However, this handicap is a costly signal since it is, for peacocks, a sign of fitness: offspring of peacocks with elaborate tails “grow and survive better under nearly natural conditions”(Petrie, 1994, p. 598). Hence the tail becomes a hard-to-fake signal directed at female peacocks. A behavior can be a costly signal if it is easily observable, costly to the actor, reliably associated with of some desirable characteristic (resources, power, skills, etc.) and lead to some evolutionary advantage such as mates, food, etc. (Smith & Bird, 2000). Costly signal theory can thus explains altruism as a behavioral costly signal: in helping unknown and unrelated individuals (when it is a perceptible and perceptibly costly behavior), the altruist individuals are in fact building social capital by hard-to-fake signals (Smith & Bird, 2004; Zahavi, 2000).

Evolutionary and psychological altruism contrast sharply. The former is a fitness-maximizing behavioral pattern whereby individuals cooperate because it promotes gene propagation and it was selected for its fitness-enhancing consequences. Biological organisms cooperate in order to maximize their inclusive fitness (the conjunction of direct and indirect fitness). Evolutionary altruisms can be found in microbes and plants as well as in birds and human (although indirect reciprocity seems to be uniquely human). Psychological altruism, most probably a capacity reserved to higher mammals or primates, is a motivation that has nothing to do with fitness (Sober & Wilson, 1998). A behavior can be evolutionary altruistic without being psychologically altruistic and vice-versa (vervet monkeys predator alarm calls). It is nonetheless possible that a psychologically altruistic behavior has fitness-enhancing consequences or that an evolutionary altruistic behavior be motivated by psychological altruism (child care for instance). One might possibly resist using the term altruism for kin discrimination, direct and indirect reciprocity, since it seems that helping another individuals so as to maximize your inclusive fitness does not sound like altruistic at all. Remember Haldane remarks, that he would give his life to save two brothers or eight cousins, since the shared genetic material is identical (quoted in McElreath & Boyd, 2007, p. 82). It seems that in the end, any kind of altruistic behavior turns out to be un-altruistic:

To extend Haldane’s famous remark, kinship can explain rescuing drowning people if they are relatives (…); reciprocal altruism if they return the favor (…); indirect reciprocity if a third party returns the favor (…) and signaling if the rescuer is judged more attractive (Farrelly et al., 2007, p. 314)

Yet if we reserve altruism solely for psychological (‘real’) altruism, it is impossible to look for an evolutionary account of altruism. “If by ‘real’ altruism we mean altruism done with the conscious intention to help, then the vast majority of living creatures are not capable of ‘real’ altruism nor therefore of ‘real’ selfishness either” (Okasha, 2005, §4).

Although psychological and evolutionary altruism are well-defined concepts they leave aside important characteristics of altruism. Take the costs and benefits, for instance. Psychological altruism, construed as a motivation, has no explicit cost or benefits. Evolutionary altruism has cost and benefits: copies of genes in the gene pool. But how can we measure whether organism X helping organism Y increases the number of X’s (or Y’s) offspring? Of course, evolutionary theory is “population thinking” (Mayr, 1959), and do not deal with single individuals in isolation. Yet, behavioral ecology (the study of animal behavior), psychology, and experimental economics do deal with individuals and need to quantify altruistic behavior. Behavioral ecologists, remark White and Crawford, “almost always ignore the number of offspring produced and study, instead, how a particular adaptation contributes to some fitness proxy, for example, net energy intake rate” (White et al., 2007, p. 276). Most of the research on cooperation deals with fitness proxies such as money, food, status: when someone donates to humanitarian organizations, it is possible to quantify how much money is donated, but not—or more difficulty—how this act increases fitness through reputation (indirect reciprocity). Similarly, cooperating in a repeated prisoner’s dilemma is direct-reciprocal, but it is not clear how it promotes genes propagation; it could be fitness-enhancing, but this is not how experimental game theory measures cooperation. Hence between evolutionary and psychological altruism I suggest we add another type of altruism: economic altruism. A behavior is economically altruistic if it benefits the recipient and it is costly to the actor; the cost and benefits are not fitness consequences, but commodities or resources (food, money, information etc.). An economically altruistic behavior could be fitness-enhancing, but need not to; it could be motivated by psychological altruism, but need not to. Economic altruism can therefore be ‘pure’ (disinterested, in which case it overlap with psychological altruism) or ‘impure” when it is motivated by a warm-glow feeling (Andreoni, 1990).

Economic altruism is therefore another category of altruistic behavior, irreducible to—but not completely independent of—psychological and biological altruism. It is the proximate, immediate, visible face of altruism and cooperation (and deeper, of morality), while evolutionary altruism is ultimate and psychological altruism is not directly observable (although neural imaging technology are now making it observable yet imprecise). Therefore, when experimental economists study how much money a subject is ready share a lab experiment, they study economic altruism (e.g. Guth & van Damme, 1998); when social psychologists study readiness to help, they study psychological altruism (e.g. Batson, 1991); and when biologists study kin recognition and nepotism in social animals, they study evolutionary altruism (e.g. Silk, 2002).

References

• Andreoni, J. (1990). Impure Altruism and Donations to Public Goods: A Theory of Warm-Glow Giving. The Economic Journal, 100(401), 464-477.
• Axelrod, R. M. (1984). The Evolution of Cooperation. New York: Basic Books.
• Batson, C. D. (1991). The Altruism Question : Toward a Social Psychological Answer. Hillsdale, N.J.: L. Erlbaum, Associates.
• Darwin, C. (1871/2000). The Descent of Man, and Selection in Relation to Sex: Adamant Media.
• Dawkins, R. (1976). The Selfish Gene. New York: Oxford University Press.
• Farrelly, D., Lazarus, J., & Roberts, G. (2007). Altruists Attract. Evolutionary Psychology, 5(2), 313-329.
• Grafen, A. (1999). Formal Darwinism, the Individual-as-Maximising-Agent Analogy, and Bet-Hedging. Proc. Roy. Soc. Ser. B, 266, 799–803.
• Grafen, A. (2002). A First Formal Link between the Price Equation and an Optimization Program. Journal of Theoretical Biology, 217(1), 75.
• Grafen, A. (2006). Optimization of Inclusive Fitness. J Theor Biol, 238(3), 541-563.
• Guth, W., & van Damme, E. (1998). Information, Strategic Behavior, and Fairness in Ultimatum Bargaining: An Experimental Study. J Math Psychol, 42(2/3), 227-247.
• Hamilton, W. D. (1964a). The Genetical Evolution of Social Behaviour. I. Journal of Theoretical Biology, 7(1), 1-16.
• Hamilton, W. D. (1964b). The Genetical Evolution of Social Behaviour. Ii. Journal of Theoretical Biology, 7(1), 17-52.
• Mayr, E. (1959). Darwin and the Evolutionary Theory in Biology. In Evolution and Anthropology: A Centennial Appraisal (pp. 409–412). Washington, D.C.: Anthropological Society of Washington.
• McElreath, R., & Boyd, R. (2007). Mathematical Models of Social Evolution : A Guide for the Perplexed. Chicago ; London: University of Chicago Press.
• Nowak, M. A. (2006). Five Rules for the Evolution of Cooperation. Science, 314(5805), 1560-1563.
• Nowak, M. A., & Sigmund, K. (2005). Evolution of Indirect Reciprocity. Nature, 437(7063), 1291-1298.
• Okasha, S. (2005). Biological Altruism. The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.), http://plato.stanford.edu/archives/sum2005/entries/altruism-biological.
• Petrie, M. (1994). Improved Growth and Survival of Offspring of Peacocks with More Elaborate Trains. Nature, 371(6498), 598-599.
• Silk, J. B. (2002). Kin Selection in Primate Groups. International Journal of Primatology, 23(4), 849-875.
• Smith, E. A., & Bird, R. B. (2004). Costly Signaling and Cooperative Behavior. In H. Gintis, S. Bowles, R. Boyd & E. Ferh (Eds.), Moral Sentiments and Material Interests : The Foundations of Cooperation in Economic Life (pp. 115-148). Cambridge, Mass.: MIT Press.
• Smith, E. A., & Bird, R. L. B. (2000). Turtle Hunting and Tombstone Opening: Public Generosity as Costly Signaling. Evolution and Human Behavior, 21(4), 245-261.
• Sober, E., & Wilson, D. S. (1998). Unto Others : The Evolution and Psychology of Unselfish Behavior. Cambridge, Mass.: Harvard University Press.
• Stich, S. (2007). Evolution, Altruism and Cognitive Architecture: A Critique of Sober and Wilson’s Argument for Psychological Altruism. Biology and Philosophy, 22(2), 267-281.
• Trivers, R. L. (1971). The Evolution of Reciprocal Altruism. Quarterly Review of Biology, 46(1), 35.
• West, S. A., Griffin, A. S., & Gardner, A. (2007). Social Semantics: Altruism, Cooperation, Mutualism, Strong Reciprocity and Group Selection. Journal of Evolutionary Biology, 20(2), 415-432.
• White, D. W., Dill, L. M., & Crawford, C. B. (2007). A Common, Conceptual Framework for Behavioral Ecology and Evolutionary Psychology. Evolutionary Psychology,, 5(2), 275-288.
• Zahavi, A. (2000). Altruism: The Unrecognized Selfish Traits. Journal of Consciousness Studies, 7, 253-256.
• Zahavi, A., & Zahavi, A. (1997). The Handicap Principle : A Missing Piece of Darwin's Puzzle. New York: Oxford University Press.

My brain has a politics of its own: neuropolitic musing on values and signal detection

Political psychology (just as politicians and voters) identifies two species of political values: left/right, or liberalism/conservatism. Reviewing many studies, Thornhill & Fincher (2007) summarizes the cognitive style of both ideologies:

Liberals tend to be: against, skeptical of, or cynical about familiar and traditional ideology; open to new experiences; individualistic and uncompromising, pursuing a place in the world on personal terms; private; disobedient, even rebellious rulebreakers; sensation seekers and pleasure seekers, including in the frequency and diversity of sexual experiences; socially and economically egalitarian; and risk prone; furthermore, they value diversity, imagination, intellectualism, logic, and scientific progress. Conservatives exhibit the reverse in all these domains. Moreover, the felt need for order, structure, closure, family and national security, salvation, sexual restraint, and self-control, in general, as well as the effort devoted to avoidance of change, novelty, unpredictability, ambiguity, and complexity, is a well-established characteristic of conservatives. (Thornhill & Fincher, 2007).

In their paper, Thornhill & Fincher presents an evolutionary hypothesis for explaining the liberalism/conservatism ideologies: both originate from innate adaptation to attachement, parametrized by early childhood experiences. In another but related domain Lakoff (2002) argued that liberals and conservatives differs in their methaphors: both view the nation or the State as a child, but they hold different perspectives on how to raise her: the Strict Father model (conservatives) or the Nurturant Parent model (liberals); see an extensive description here). The first one

posits a traditional nuclear family, with the father having primary responsibility for supporting and protecting the family as well as the authority to set overall policy, to set strict rules for the behavior of children, and to enforce the rules [where] [s]elf-discipline, self-reliance, and respect for legitimate authority are the crucial things that children must learn.

while in the second:

Love, empathy, and nurturance are primary, and children become responsible, self-disciplined and self-reliant through being cared for, respected, and caring for others, both in their family and in their community.

In the October issue of Nature Neuroscience, a new research paper by Amodio et al. study the "neurocognitive correlates of liberalism and conservatism". The study is more modest than the title suggests. Subject were submitted to the same test, a Go/No Go task (click when you see a "W" don't click when it's a "M"). The experimenters then trained the subjects to be used to the Go stimuli; on a few occasions, they were presented with the No Go stimuli. Since they got used to the Go stimuli, the presentation of a No Go creates a cognitive conflict: balancing the fast/automatic/ vs. the slow/deliberative processing. You have to inhibit an habit in order to focus on the goal when the habit goes in the wrong direction. The idea was to study the correlation between political values and conflict monitoring. The latter is partly mediated by the anterior cingulate cortex, a brain area widely studied in neuroeconomics and decision neuroscience (see this post). EEG recording indicated that liberals' neural response to conflict were stronger when response inhibition was required. Hence liberalism is associated to a greater sensibility to response conflict, while conservatism is associated with a greater persistence in the habitual pattern. These results, say the authors, are

consistent with the view that political orientation, in part, reflects individual differences in the functioning of a general mechanism related to cognitive control and self-regulation

Thus valuing tradition vs. novelty, security vs. novelty might have sensorimotor counterpart, or symptoms. Of course, it does not mean that the neural basis of conservatism is identified, or the "liberal area", etc, but this study suggest how micro-tasks may help to elucidate, as the authors say in the closing sentence, "how abstract, seemingly ineffable constructs, such as ideology, are reflected in the human brain."

What this study--together with other data on conservatives and liberal--might justify is the following hypothesis: what if conservatives and liberals are natural kinds? That is, "homeostatic property clusters", (see Boyd 1991, 1999), categories of "things" formed by nature (like water, mammals, etc.), not by definition? (like supralunar objects, non-cat, grue emerald, etc.) Things that share surface properties (political beliefs and behavior) whose co-occurence can be explained by underlying mechanims (neural processing of conflict monitoring)? Maybe our evolution, as social animals, required the interplay of tradition-oriented and novelty-oriented individuals, risk-prone and risk-averse agents. But why, in the first place, evolution did not select one type over another? Here is another completely armchair hypothesis: in order to distribute, in the social body, the signal detection problem.

What kind of errors would you rather do: a false positive (you identify a signal but it's only noise) or a false negative (you think it's noise but it's a signal)? A miss or a false alarm? That is the kind of problems modeled by signal detection theory (SDT): since there is always some noise and you try to detect signal, you cannot know in advance, under radical uncertainty, what kind of policy you should stick to (risk-averse or risk-prone. "Signal" and "noise" are generic information-theoretic terms that may be related to any situation where an agent tries to find if a stimuli is present:

Is is rather ironic that signal detection theorists employ the term liberal* and conservative* (the "*" means that I am talking of SDT, not politics) to refer to different biases or criterions in signal detection. A liberal* bias is more likely to set off a positive response ( increasing the probability of false positive), whereas a conservative* bias is more likely to set off a negative response (increasing the probability of false negative). The big problem in life is that in certain domains conservatism* pay, while in others it's liberalism* who does (see Proust 2006): when identifying danger, a false negative is more expensive (better safe than sorry) whereas in looking for food a false positive can be more expensive better (better satiated than exhausted). So a robust criterion is not adaptive; but how to adjust the criterion properly? If you are an individual agent, you must altern between liberal* and conservative* criterion based on your knowledge. But if you are part of a group, liberal* and conservative* biases may be distributed: certains individuals might be more liberals* (let's send them to stand and keep watch) and other more conservatives* (let's send them foraging). Collectively, it could be a good solution (if it is enforced by norms of cooperation) to perpetual uncertainty and danger. So if our species evolved with a distribution of signal detection criterions, then we should have evolved different cognitive styles and personality traits that deal differently with uncertainty: those who favor habits, traditions, security, and the others. If liberal* and conservative* criterions are applied to other domains such as family (an institution that existed before the State), you may end up with the Strict Father model and the Nurturant Parent model; when these models are applied to political decision-making, you may end up with liberals/conservatives (no "*"). That would give a new meaning to the idea that we are, by nature, political animals.


Related posts

• A Neuropolitic Look at Political Psychology
• The Political Brain
• A Neuroecomic Picture of Valuation
  

Links

• A clear discussion of the study at The Cognitive Daily.
• Political Psychology (Blackwell Publishing Journal)
• See their special issue: Political Psychology and Social Neuroscience: Strange Bedfellows or Comrades in Arms?, especially this review paper.
• Neuropolitics.org (Ezine)
• Neuropolitics mailing list.
• A presentation of Darren Schreiber research (not professor at UCSD in the Political Science Department) on neural studies of differences between political novices and sophisticates : "When asked political questions, political novices show higher activation in the prefrontal lobes, where deliberative thinking takes place. Political sophisticates show higher levels of temporal lobe activity, which suggests they 'have more meaning attached to these questions' "

References

• Amodio, D. M., Jost, J. T., Master, S. L., & Yee, C. M. (2007). Neurocognitive correlates of liberalism and conservatism. Nature Neuroscience, 10(10), 1246-1247
• Boyd, R. (1991). Realism, Anti-Foundationalism and the Enthusiasm for Natural Kinds. Philosophical Studies, 61(1 - 2), 127.
• Boyd, R. (1999). Kinds, Complexity and Multiple Realization. Philosophical Studies, 95(1 - 2), 67.
• Lakoff, G. (2002). Moral Politics: How Liberals and Conservatives Think. Chicago: University of Chicago Press (read chapter 2 here)
• Proust, J. (2006 ). Metacognition and Animal Rationality. In S. Hurley & M. Nudds (Eds.), Rational Animals. Oxford: Oxford University Press.
  
• Thornhill, R., & Fincher, C. L. (2007). What is the relevance of attachment and life history to political values? Evolution and Human Behavior, 28(4), 215-222.
• Thorisdottir, H., Jost, J. T., Liviatan, I., & Shrout, P. E. (2007). Psychological Needs and Values Underlying Left-Right Political Orientation: Cross-National Evidence from Eastern and Western Europe. Public Opin Q, nfm008.

Biology of Societies: A Special Issue of Current Biology

Recommended reading for anybody interested in social cognition, sociality, and biology: The last issue of Current Biology is devoted to the Biology of Societies:

• Frank, S. A. (2007). All of life is social. Current Biology, 17(16), R648-R650.
• Jackson, D. E. (2007). Social spiders. Current Biology, 17(16), R650-R652.
• Clayton, N. S., & Emery, N. J. (2007). The social life of corvids. Current Biology, 17(16), R652-R656.
• Watts, H. E., & Holekamp, K. E. (2007). Hyena societies. Current Biology, 17(16), R657-R660.
• West, S. A., Griffin, A. S., & Gardner, A. (2007). Evolutionary Explanations for Cooperation. Current Biology, 17(16), R661-R672.
• Boomsma, J. J. (2007). Kin Selection versus Sexual Selection: Why the Ends Do Not Meet. Current Biology, 17(16), R673-R683.
• Shaulsky, G., & Kessin, R. H. (2007). The Cold War of the Social Amoebae. Current Biology, 17(16), R684-R692.
• Cremer, S., Armitage, S. A. O., & Schmid-Hempel, P. (2007). Social Immunity. Current Biology, 17(16), R693-R702.
• Leadbeater, E., & Chittka, L. (2007). Social Learning in Insects -- From Miniature Brains to Consensus Building. Current Biology, 17(16), R703-R713.
• Byrne, R. W., & Bates, L. A. (2007). Sociality, Evolution and Cognition. Current Biology, 17(16), R714-R723.
• Frith, C. D., & Frith, U. (2007). Social Cognition in Humans. Current Biology, 17(16), R724-R732.

“Note that he relies on you”; how a single sentence enhances altruism in a Dictator game

In a recent study, experimental economist Pablo Branas-Garza showed that a single sentence is enough to promote fairness. He conducted two experiments, one in a classroom, the other being a regular economic experiments, where subjects had to play a Dictator Game. In every experiments, there was a baseline condition (subjects where presented with a description of the game), and a framing condition: at the end of the text, a sentence reads “Note that your opponent relies on you”. Results: adding that sentence increased donations. As fig. 1 shows, the framing boosts altruism and reduces selfishness: low offers are much rarer.

fig. 1, from Branas-Garza, 2007.

What is surprising is not that subjects are sensible to certain moral-social cues, but that such a simple cue (7 words) is sufficient. The more we know about each others, the less selfish we are.

• Branas-Garza, P. (2007). Promoting helping behavior with framing in dictator games. Journal of Economic Psychology, 28(4), 477-486.

Greed—for lack of a better word—is not necessarily good: the other Adam Smith and the economics of altruism

In one of the most quoted passage of the Wealth of Nations, Adam Smith argue that economic self-interest leads to collective optima:

It is not from the benevolence of the butcher, the brewer or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves not to their humanity but to their self-love, and never talk to them of our necessities but of their advantages. Nobody but a beggar chooses to depend chiefly upon the benevolence of their fellow-citizens.

Everybody will remember the famous Gordon Gekko's speech in Oliver Stone's Wall Street (1987):

The point is, ladies and gentlemen, that greed—for lack of a better word—is good. Greed is right. Greed works. Greed clarifies, cuts through, and captures the essence of the evolutionary spirit. Greed, in all of its forms—greed for life, for money, for love, knowledge—has marked the upward surge of mankind.

Things may not be that simple. While the standard Homo Economicus model represents agents as exclusively motivated by their material self-interest, economic theories of fairness put forth the picture of Homo Reciprocans, an agent whose utility function incorporates social parameters (Bowles & Gintis, 2002; see Fehr and Schmidt, 2003, for a review). Economic theories of fairness fall into two categories: outcome-based models and intention-based models. The former explains fairness as the product of players’ aversion to inequity (Bolton and Ockenfels, 2000; Fehr and Schmidt, 1999; see also this post). Players are sensible to the distributive consequences of strategic interactions and prefer resources allocations that reduce inequity: they negatively value a discrepancy between their own payoff and an equitable payoff (whether it’s the mean payoff or another player’s payoff). The latter explains fairness as the product of players’ reciprocation of perceived kindness or unkindness (Rabin, 1993 ; Dufwenberg & Kirchsteiger, 2004).). More than the outcome of an interaction, fairness is motivated by the attributed intention. For instance, in a ultimatum where the proposer’s behavior is restricted to two options (50/50 and 80/20 split), the second option is the most rejected; when the proposer’s options are 20/80 and 80/20, however, the first option is rejected less often (Falk, Fehr & Fischbacher 2003). Decision-makers value differently the same option whether it is perceived as an intention to be fair (valued positively) or not (negatively). Since both parameters appear to be important, many models integrate both intentions and outcomes (Fehr & Schmidt, 2003; Falk & Fischbacher, 2006).
A common feature of these models is the preservation of the optimality assumption: although they all suggest that standard utility function should incorporate different parameters, they do not reject the idea that agents are internally rational: they maximize a non-classical utility function.

Hence it is not surprising that contemporary research is more interested by the "first" Adam Smith, who wrote in the Theory of Moral Sentiments:

How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it. Of this kind is pity or compassion, the emotion which we feel for the misery of others, when we either see it, or are made to conceive it in a very lively manner. That we often derive sorrow from the sorrow of others, is a matter of fact too obvious to require any instances to prove it; for this sentiment, like all the other original passions of human nature, is by no means confined to the virtuous and humane, though they perhaps may feel it with the most exquisite sensibility. The greatest ruffian, the most hardened violator of the laws of society, is not altogether without it.

In "Adam Smith, Behavioral Economist", Ashraf et al. (2005, The Journal of Economic Perspectives, 19, 131-145) discusses the relevance of Smith for experimental economics. In "The Two Faces of Adam Smith" (Southern Economic Journal, 65, 1-19), another Smith (Vernon) analyses the dual nature of Smith's (Adam) writing.

Finally, (found thanks to Mind Hacks) there is an excellent paper in the last Scientific American on the economics of fairness and other moral sentiments:

Is Greed Good?
Economists are finding that social concerns often trump selfishness in financial decision making, a view that helps to explain why tens of millions of people send money to strangers they find on the Internet
By Christoph Uhlhaas

There will be a conference a conference to commemorate the 250th anniversary of The Theory of Moral Sentiments in 2009 in Oxford (see CFP on PhilEcon website).

References

• Ashraf, N., Camerer, C. F., & Loewenstein, G. (2005). Adam Smith, Behavioral Economist. The Journal of Economic Perspectives, 19, 131-145.
  
• Bolton, G. E., & Ockenfels, A. (2000). ERC: A Theory of Equity, Reciprocity, and Competition. The American Economic Review, 90(1), 166-193.
• Bowles, S., & Gintis, H. (2002). Behavioural science: Homo reciprocans. Nature, 415(6868), 125-128.
• Bowles, S., & Gintis, H. (2004). The evolution of strong reciprocity: cooperation in heterogeneous populations. Theoretical Population Biology, 65(1), 17-28.
• Dufwenberg, M., & Kirchsteiger, G. (2004). A theory of sequential reciprocity. Games and Economic Behavior, 47(2), 268-298.
• Falk, A., Fehr, E., & Fischbacher, U. (2003). On the Nature of Fair Behavior. Economic Inquiry, 41(1), 20-26.
• Falk, A., & Fischbacher, U. (2006). A theory of reciprocity. Games and Economic Behavior, 54(2), 293-315.
• Fehr, E., & Fischbacher, U. (2002). Why social preferences matter: The impact of non-selfish motives on competition, cooperation and incentives. Economic Journal, 112, C1-C33.
• Fehr, E., Fischbacher, U., & Gachter, S. (2002). Strong reciprocity, human cooperation, and the enforcement of social norms. Human Nature, 13(1), 1-25.
• Fehr, E., & Rockenbach, B. (2004). Human altruism: economic, neural, and evolutionary perspectives. Curr Opin Neurobiol, 14(6), 784-790.
• Fehr, E., & Schmidt, K. (2003). Theories of Fairness and Reciprocity – Evidence and Economic Applications. In M. Dewatripont, L. Hansen & S. Turnovsky (Eds.), Advances in Economics and Econometrics - 8th World Congress (pp. 208-257).
• Fehr, E., & Schmidt, K. M. (1999). A Theory Of Fairness, Competition, and Cooperation. Quarterly Journal of Economics, 114(3), 817-868.
• Rabin, M. (1993). Incorporating Fairness into Game Theory and Economics. The American Economic Review, 83(5), 1281-1302.
• Smith, V. L. (1998). The Two Faces of Adam Smith. Southern Economic Journal, 65, 1-19.
  

Kahneman and Sunstein on moral psychology and institutions

What does a professor of law and political Science and a Nobel-prize winning economic psychologist/behavioral economist can write about? The interplay of cognition and institution, of course ! In a paper posted on the SSRN website, Kahneman and Sunstein discuss how the combination of dual-process theories of cognition (the idea that we have a fast and intuitive "System I" and a deliberative "System II") and research on moral intuitions can help understanding institutional decision-making:

Moral intuitions operate in much the same way as other intuitions do; what makes the moral domain is distinctive is its foundations in the emotions, beliefs, and response tendencies that define indignation. The intuitive system of cognition, System I, is typically responsible for indignation; the more reflective system, System II, may or may not provide an override. Moral dumbfounding and moral numbness are often a product of moral intuitions that people are unable to justify. An understanding of indignation helps to explain the operation of the many phenomena of interest to law and politics: the outrage heuristic, the centrality of harm, the role of reference states, moral framing, and the act-omission distinction. Because of the operation of indignation, it is extremely difficult for people to achieve coherence in their moral intuitions. Legal and political institutions usually aspire to be deliberative, and to pay close attention to System II; but even in deliberative institutions, System I can make some compelling demands.

[found thanks to The Brooks blog]

On dual-process theories of reasoning, see Stanovich , Keith E. and West, Richard F. (2000) Individual Differences in Reasoning: Implications for the Rationality Debate?.(BBS online archive).


References:

• Kahneman, Daniel and Sunstein, Cass R., "Indignation: Psychology, Politics, Law" (July 2007). U of Chicago Law & Economics, Olin Working Paper No. 346 Available at SSRN: http://ssrn.com/abstract=1002707

Understanding two models of fairness: outcome-based inequity aversion vs. intention-based reciprocity

Why are people fair? Theoretical economics provides two generic models that fits the data. According to the first, inequity aversion, people are inequity-averse: they don't like a situation where one agent is disadvantaged over another. This model is based on consequences. The other model is based on intentions: although the consequences of an action are important, what matters here is the intention that motivates the action. I won't discuss which approach is better (it is an ongoing debates in economics), but I just wanted to share with a extremely clear presentations of the two parties, found in van Winden, F. (2007). Affect and Fairness in Economics. Social Justice Research, 20(1), 35-52., on pages 38-39:

In inequity aversion models (Bolton and Ockenfels, 2000; Fehr and Schmidt, 1999), which focus on the outcomes or payoffs of social interactions, any deviation between an individual's payoff and the equitable payoff (e.g., the mean payoff or the opponent's payoff) is supposed to be negatively valued by that individual. More formally, the crucial difference between an outcome-based inequity aversion model and the homo economicus model is that, in addition to the argument representing the individual's own payoff, a new argument is inserted in the utility function showing the individual's inequity aversion (social preferences), as in the social utility model (see, e.g., Handgraaf et al., 2003; Loewenstein et al., 1989; Messick and Sentis, 1985). The individual is then assumed to maximize this adapted utility function.

In intention-based reciprocity models it is not the outcomes of the interaction as such that matter, but the intentions of the players (Rabin, 1993; see also Falk and Fischbacher, 2006). The idea is that people want to reciprocate perceived (un)kindness with (un)kindness, because this increases their utility. Obviously, beliefs play a crucial role here. More formally, in this case, in addition to an individual's own payoff a new argument is inserted in the utility function incorporating the assumed reciprocity motive. As a consequence, if someone is perceived as being kind it increases the individual's utility to reciprocate with being kind to this other person. Similarly, if the other is believed to be unkind, the individual is better off by being unkind as well, because this adds to her or his utility. Again, this adapted utility function is assumed to be maximized by the individual.

A glimpse at the evolution of the fearing and trusting brain

Together with other mechanisms, the amygdala is involveld in a complex neural circuitry that transforms photons hitting your eyes into the feeling that "Mom is mad at me because I break her favorite vase". Often referred to as the fear center, the amygdala is more like an online supervisory system that sets levels of alert. Many of its activities are of a social nature. Explicit and implicit distrust of faces elicits amygdala activation (Winston et al., 2002), while trust is increased with amygdala impairment (Adolphs et al., 1998). Moreover, the trust enhancing effect of oxytocin is mediated by amygdalar modulation: oxytocin reduces fear and hence allows trusting. In a nutshell, emotional memorization, learning and modulation performed by the amygdala obeys the following flowchart:

(from Schumann 1998)

A subpart of the amygdala, the lateral nucleus, processes information about social stimuli (such as facial expression). Autistic individuals tend to have impaired lateral nucleus, which makes sense if this nucleus is an important social-cognitive device (autistic subjects perform poorly in task that involves mental states attribution or other social inferences).According to Emery and Amaral (2000), inputs form the visual neocortex cortex enters the amygdala through the lateral nucleus, where its "emotional meaning" is attributed (I know, it is simplification...); the basal nucleus adds information about the social context. Hence this nucleus acts as a sensory integrator (LeDoux, 2000).

In a new paper in American Journal of Physical Anthropology, Barger et al. studied the relative size of different nuclei of the amygdala in different primates (humans, chimpanzee, bonobo, gorilla, etc.). The study revealed that the human lateral nucleus represents a larger fraction of the amygdala:

The authors conclude:

The large size of the human L [lateral nuclei] may reflect the proliferation of the temporal lobe over the course of hominid evolution, while the inverse may be true of the gorilla. The smaller size of the orangutan AC [amygdaloid complex] and BLD [Baso-lateral division] may be related to the diminished importance of interconnected limbic structures in this species. Further, there is some evidence that the orangutan, which exhibits one of the smallest group sizes on the contin- uum of primate sociality, may also be distinguished neuroanatomically from the other great apes, suggesting that social pressures may play a role in the development of the AC in association with other limbic regions.

Living in large groups thus may have shaped the evolution of emotional processing capacities of our brains. In the economy of nature, negotiating our way in a complex social world requires accute and specialized cognitive capacities in order to cooperate, trust, reciprocate, etc. This research show the potentials of evolutionary cognitive neuroscience (see this post).


References

• Adolphs R, Tranel D, Damasio AR (1998) The human amygdala in social judgment. Nature 393: 470-474.
• Barger, N. Stefanacci, L., & Semendeferi, K. (2007) A comparative volumetric analysis of the amygdaloid complex and basolateral division in the human and ape brain. American Journal of Physical Anthropology.
• Emery and Amaral, 2000 N.J. Emery and D.G. Amaral, The role of amygdala in primate social cognition. In: R.D. Lane and L. Nadel, Editors, Cognitive Neuroscience of Emotion, Oxford Univ. Press, New York (2000), pp. 156–191.
• LeDoux JE (2000) Emotion circuits in the brain. Annu Rev Neurosci 23: 155-184
• Schumann, J.A. 1998. Language Learning. Vol. 48 Issue s1 Page ix-326
• Winslow JT, Insel TR (2004) Neuroendocrine basis of social recognition. Curr Opin Neurobiol 14: 248-253
• 
  

The moral stance: a brief introduction to the Knobe effect and similar phenomena

An important discovery in the new field of Experimental Philosophy (or "x-phi", i.e., "using experimental methods to figure out what people really think about particular hypothetical cases" -Online dictionary of philosophy of mind) is the importance of moral beliefs in intentional action attribution. Contrast these two cases:

[A] The vice-president of a company went to the chairman of the board and said, ‘We are thinking of starting a new program. It will help us increase profits, but it will also harm the environment.’ The chairman of the board answered, ‘I don’t care at all about harming the environment. I just want to make as much profit as I can. Let’s start the new program.’ They started the new program. Sure enough, the environment was harmed.

[B] The vice-president of a company went to the chairman of the board and said, ‘We are thinking of starting a new program. It will help us increase profits, and it will also help the environment.’ The chairman of the board answered, ‘I don’t care at all about helping the environment. I just want to make as much profit as I can. Let’s start the new program.’ They started the new program. Sure enough, the environment was helped.

A and B are identical, except that in one case the program harms the environment and in the other case it helps it. Subjects were asked whether the chairman of the board intentionally harm (A) or help (B) the environment. Since the two cases have the same belief-desire structure, both actions should be seen as intentional, whether it is right or wrong. It turns out that in the "harm" version, most people (82%) say that the chairman intentionally harm the environment; in the "help" version, only 23% say that the chairman intentionally help the environment. This effect is call the "Knobe effect", because it was discovered by philosopher Joshua Knobe. In a nutshell it means that

people’s beliefs about the moral status of a behavior have some influence on their intuitions about whether or not the behavior was performed intentionally (Knobe, 2006, p. 207)

Knobe replicated the experiment with different populations and methodology and the result is robust (see his 2006, for a review). It seems that humans are more prone to think that someone is responsible for an an action if the outcome is morally wrong. Contrary to common wisdom, the folk-psychological concept of intentional action does not--or not primarily--aim at explaining and predicting action, but at attributing praise and blame. There is something morally normative to saying that "A does X".

A related post on the x-phi blog by Sven Nyholm describes a similar experiment. The focus was not intention, but happiness. The two versions were

[A] Richard is a doctor working in a Red Cross field hospital, overseeing and carrying out medical treatment of victims of an ongoing war. He sometimes gets pleasure from this, but equally often the deaths and human suffering get to him and upset him. However, Richard is convinced that this is an important and crucial thing he has to do. Richard therefore feels a strong sense of satisfaction and fulfillment when he thinks about what he is doing. He thinks that the people who are being killed or wounded in the war don’t deserve to die, and that their well-being is of great importance. And so he wants to continue what he is doing even though he sometimes finds it very upsetting.

[B] Richard is a doctor working in a Nazi death camp, overseeing and carrying out executions and nonconsensual, painful medical experiments on human beings. He sometimes gets pleasure from this, but equally often the deaths and human suffering get to him and upset him. However, Richard is convinced that this is an important and crucial thing that he has to do. Richard therefore feels a strong sense of satisfaction and fulfillment when he thinks about what he is doing. He thinks that the people who are being killed or experimented on don’t deserve to live, and that their well-being is of no importance. And so he wants to continue what he is doing even though he sometimes finds it very upsetting.

Subjects were asked whether they agreed or disagreed with the sentence "Richard is happy" (on a scale from 1=disagree to 7=agree). Subjects slightly agrees (4.6/7) in the morally good condition (A) whereas they slightly disagrees (3.5/7) in the morally bad condition (B), and the difference is statistically significant. Again, the concept of "being happy" is partly moral-normative.

A related phenomena has been observed in an experimental study of generosity recently published: generous behavior is also influenced by moral-normative beliefs (Fong, 2007). In this experiment, donors had to decide how much of a $10 dollars "pie" they want to transfer to a real-life welfare recipient (and keep the rest: thus it is a Dictator game). They read information about the recipients (who had to fill a questionnaire before). They we asked about their age, race, gender, etc. The three recipients had a similar profile, except for their motivation to work. In the last three questions:

• If you don't work full-time, are you looking for more work? ______Yes, I am looking for more work. ______No, I am not looking for more work.
• If it were up to you, would you like to work full-time? ______Yes, I would like to work full-time. ______No, I would not like to work full-time.
• During the last five years, have you held one job for more than a one-year period? Yes_____ No_____

one replied Yes to all ("industrious"), one replied No ("lazy"), and the other did not reply ("low-information"). Donors made their decision and money was transferred for real (btw, that's one thing I like about experimental economics: there is no deceptions, no as-if: real people receive real money). Results:

Lazy-recipient, low-information-recipient, and industrious-recipient received an average of $1.84, $3.21, and $2.79, respectively. The ant and the grasshopper! (" You sang! I'm at ease/
For it's plain at a glance/Now, ma'am, you must dance."). As the author says:

Attitudinal measures of beliefs that the recipient in the experiment was poor because of bad luck rather than laziness – instrumented by both prior beliefs that bad luck rather than laziness causes poverty and randomly provided direct information about the recipient's attachment to the labour force – have large and very robust positive effects on offers

[In another research paper Pr. Fong also found different biases in giving to Katrina victims.]

An interesting--and surprising--finding of this study is also that this "ant effect" ("you should deserve help") was stronger in people who scored higher of humanitarianism beliefs. They don't give more than others when recipients are deemed to be poor because of laziness (another reason not to trust what people say about themselves, and look at their behavior instead). Again, a strong moral-normative effect on beliefs and behavior. Since oxytocin increases generosity (see this post) and this effect is due to a greater empathy induced by oxytocin, I am curious to see if people in the lazy vs. industrious experiment after oxytocin inhalation would become more sensible to the origin of poverty (bad luck or lazyness). If bad luck inspires more empathy, then I guess yes.

Man the moral animal?

Morality seems to be deeply entrenched in our social-cognitive mechanims. One way to understand all these results is to posit that we routinely and usually interpret each other from the "moral stance", not the intentional one. The "intentional stance", as every Philosophy of mind 101 course teaches us, is the perspective we adopt when we deal with intentional agents (agents who entertain beliefs and desires). We explain and predict action based on their rationality and the mental representations they should have, given the circumstances. In other words, it's the basic toolkit for being a game-theoretic agent. Philosophers (Dennett in particular) contrast this stance with the physical and the design stance (when we talk about an apple that falls or the function of the "Ctrl" key in a computer, for instance). I think we should introduce a related stance, the moral stance. Maybe--but research will tell us--this stance is more basic. We switch to the purely intentional stance when, for instance, we interact with computer in experimental games. Remember how subjects don't care about being cheated by a computer in the Ultimatum Game: they have no aversive feeling (i.e. insular activation) when the computer make an unfair offer (see a discussion in this paper by Sardjevéladzé and Machery). Hence they don't use the "moral stance", but they still use the intentional stance. Another possibility is that the moral stance might explains why people deviate from standard game-theoretical predictions: all these predictions are based on intentional-stance functionalism. This stance applies more to animals, psychopaths or machines than to normal human beings. And also to groups: in many games, such as the Ultimatum of the Centipede, groups behave more "rationally" than individuals (see Bornstein et al., 2004; Bornstein & Yaniv, 1998; Cox & Hayne, 2006), that is, they are closer to game-theoretic behavior (a point radically develop in the movie The Corporation: firms lack moral qualities). Hence the moral stance may have particular requirements (individuality, emotions, empathy, etc.).

References:

• Cox, J., & Hayne, S. (2006). Barking up the right tree: Are small groups rational agents? Experimental Economics, 9(3), 209-222.
  
• Bornstein, G., Kugler, T., & Ziegelmeyer, A. (2004). Individual and group decisions in the centipede game : Are groups more "rational" players? Journal of Experimental Social Psychology, 40, 599-605.
• Bornstein, G., & Yaniv, I. (1998). Individual and group behavior in the ultimatum game: Are groups more “rational” players? Experimental Economics, 1(1), 101-108.
• Fong, C. M. (2007). Evidence from an Experiment on Charity to Welfare Recipients: Reciprocity, Altruism and the Empathic Responsiveness Hypothesis. The Economic Journal, 117(522), 1008-1024.
• Fong, C. and Luttmer, E. “What Determines Giving to Hurricane Katrina Victims? Experimental Evidence on Income, Race and Fairness.” NBER Working Paper #13219.
• Knobe, J. (2006). The Concept of Intentional Action: A Case Study in the Uses of Folk Psychology. Philosophical Studies, 130(2), 203-231.
• Dennett, D. "Three kinds of intentional psychology" (IP) in Heil, J. - Philosophy of Mind: A guide and anthology, Clarendon Press, Oxford, 2004
• Sardjevéladzé and Machery, Trusting and Punishing Artifacts.

Links:

• Knobe, J. (forthcoming). What Is Experimental Philosophy? The Philosophers' Magazine.
• Experimental Philosophy - Online dictionary of philosophy of mind entry.
  
• X-Phi blog
• Explaining the Knobe effect
• Knobe homepage
• Slate article on X-Phi
  
• A special issue of Philosophical Explorations on X-Phi:
  - Kauppinen, Antti (2007). THE RISE AND FALL OF EXPERIMENTAL PHILOSOPHY. Philosophical Explorations, 10 (2), 1386-9795.
  - Knobe, Joshua (2007). EXPERIMENTAL PHILOSOPHY AND PHILOSOPHICAL SIGNIFICANCE. Philosophical Explorations, 10 (2), 1386-9795.
  - Nadelhoffer, Thomas & Nahmias, Eddy (2007). THE PAST AND FUTURE OF EXPERIMENTAL PHILOSOPHY. Philosophical Explorations, 10 (2), 1386-9795.
  
  

More than Trust: Oxytocin Increases Generosity

It was known since a couple of years that oxytocin (OT) increases trust (Kosfeld, et al., 2005): in the Trust game, players transfered more money once they inhale OT. Now recent research also suggest that it increases generosity. In a paper presented at the ESA (Economic Science Association, an empirically-oriented economics society) meeting, Stanton, Ahmadi, and Zak, (from the Center for Neuroeconomics studies) showed that Ultimatum players in the OT group offered more money (21% more) than in the placebo group--$4.86 (OT) vs. $4.03 (placebo).
They defined generosity as "an offer that exceeds the average of the MinAccept" (p.9), i.e., the minimum acceptable offer by the "responder" in the Ultimatum. In this case, offers over $2.97 were categorized as generous. Again, OT subjects displayed more generosity: the OT group offered $1.86 (80% more) over the minimum acceptable offer, while placebo subjects offered $1.03.

Interestingly, OT subjects did not turn into pure altruist: they make offers (mean $3.77) in the Dictator game similar to placebo subjects (mean $3.58, no significant difference). Thus the motive is neither direct nor indirect reciprocity (Ultimatum were blinded one-shot so there is no tit-for-tat or reputation involved here). It is not pure altruism, according to Stanton et al., (or "strong reciprocity"--see this post on the distinction between types of reciprocity) because the threat of the MinAccept compels players to make fair offers. They conclude that generosity in enhanced because OT affects empathy. Subjects simulate the perspective of the other player in the Ultimatum, but not in the Dictator. Hence, generosity "runs" on empathy: in empathizing context (Ultimatum) subjects are more generous, but in non-empathizing context they don't--in the dictator, it is not necessary to know the opponent's strategy in order to compute the optimal move, since her actions has no impact on the proposer's behavior. It would be interesting to see if there is a different OT effect in basic vs. reenactive empathy (sensorimotor vs. deliberative empathy; see this post).

Interested readers should also read Neural Substrates of Decision-Making in Economic Games, by one of the author of the study (Stanton): in her PhD Thesis, she desribes many neurpeconomic experiences.

[Anecdote: I once asked people of the ESA why they call their society like that: all presented papers were experimental, so I thought that the name should reflect the empirical nature of the conference. They replied judiscioulsy : "Because we think that it's how economics should be done"...]

References

• Kosfeld, M., Heinrichs, M., Zak, P. J., Fischbacher, U., & Fehr, E. (2005). Oxytocin increases trust in humans. Nature, 435(7042), 673-676.
• Stanton, A. A. (2007): Neural Substrates of Decision-Making in Economic Games. Published in: Journal of Dissertation Issue 1.Volume 1 (2007): pp. 1-63.
• Stanton, A. A., Ahmadi, S., & Zak, P. J. (2007). Oxytocin Increases Generosity. Paper presented at the Economic Science Association 2007 World Meeting.

The linguistic basis of social preferences

Surprising (at least to me) finding, published in PNAS today. Young infants display a strong preference for agents that speak their own language. More than smell, look, and sound, social attachment seems to be mediated by linguistic (and accent) similarity. We like those who speak like us. From this findings, researchers draw three conclusions:

First, language provides a cue to social preferences, even in infants who have not begun to produce or understand speech. Second, the tendency to favor otherwise unfamiliar members of one's own social group begins to emerge early in human life and well before children begin to learn about the nature and history of social-group conflicts. The passage from infants' social preferences to adults' social conflicts may be long and circuitous, but such a path may exist and may explain, in part, why conflicts among different language and social groups are pervasive and difficult to eradicate. Third, because human languages vary, and the native language must be learned, the tendency to make social distinctions is shaped by experience. Because language learning is especially adaptable early in development, social preferences also may be malleable at young ages. This early adaptability of preference formation for familiar characteristics of individuals may obtain for many potential indicators of social group membership.

• Katherine D. Kinzler, Emmanuel Dupoux, and Elizabeth S. Spelke. The native language of social cognition. PNAS 104: 12577-12580
  

Altruism: a research program

Phoebe: I just found a selfless good deed; I went to the park and let a bee sting me.
Joey: How is that a good deed?
Phoebe: Because now the bee gets to look tough in front of his bee friends. The bee is happy and I am not.
Joey: Now you know the bee probably died when he stung you?
Phoebe: Dammit!
- [From Friends, episode 101]

Altruism is a lively research topic. The evolutionary foundations, neural substrates, psychological mechanisms, behavioral manifestations, formal modeling and philosophical analyses of cooperation constitute a coherent—although not unified—field of inquiry. See for instance how neuroscience, game theory, economic, philosophy, psychology and evolutionary theory interact in Penner et al. 2005; Hauser 2006; Fehr and Fischbacher 2002; Fehr and Fischbacher 2003. The nature of prosocial behavior, from kin selection to animal cooperation to human morality can be considered as a progressive Lakatosian research programs. Altruism has a great conceptual "sex-appeal" because it is mystery for two types of theoreticians: biologists and economists. They both wonder why an animal or an economic agent would help another: since these agents maximize fitness/utility, altruistic behavior is suboptimal. Altruims (help, trust, fairness, etc.) seems intuitively incoherent with economic rationality and biological adaptation, with markets and natural selection. Or is it?

In the 60's, biologists challenged the idea that natural selection is incompatible with altruism. Hamilton (1964a, 1964b) and Trivers (1971) showed that biological altruism makes sense. An animal X might behave altruistically toward another Y because they are genetically related: in doing so, X maximize the copying of its gene, since many of its genes will be hosted in Y. Thus the more X and Y are genetically related, the more X will be ready to help Y. This is kin altruism. Altruism can also be reciprocal: scratch my back and I'll scratch yours. Tit-for-tat, or reciprocal altruism also makes sense because by being altruistic, one may augments its payoff. X helps Y, but the next time Y will help X; thus it is better to help than not to help. In both cases, the idea is that altruism is a mean not an end. Others argue that more complex types of altruisms exists. For instance, X can help Y because Y already helped Z (indirect reciprocity). In this case, the tit-for-tat logic is extended to agents that the helper did not meet in the past. Generalized reciprocity (see this previous post) is another type of altruism: helping someone because someone helped you in the past. This altruism does not require memory or personal identification. X helps someone because someone else helped X. Finally, Strong reciprocity is the idea that humans display genuine altruism: strong reciprocators cooperate with cooperators, do not cooperate with cheaters, and are ready to punish cheaters even at a cost to themselves. Their proponents argue that it evolved through group selection.

Experimental economics and neuroeconomics also challenged the idea of rational, greedy, selfish actor (the Ayn Rand hero). Experimental game theory showed that, contrarily to orthodox game theory, subjects cooperate massively in prisoner’s dilemma (Ledyard, 1995; Sally, 1995). Rilling et al. showed that players enjoy cooperating. Players who initiate and players who experience mutual cooperation display activation in nucleus accumbens and other reward-related areas such as the caudate nucleus, ventromedial frontal/orbitofrontal cortex, and rostral anterior cingulate cortex (Rilling et al., 2002). In another experiment, the presentation of faces of intentional cooperators caused increased activity in reward-related areas (Singer et al. 2004). In the ultimatum game, proposers make ‘fair’ offers, about 50% of the amount, responders tend to accept these offers and reject most of the ‘unfair’ offers (less than 20%;Oosterbeek et al., 2004). Brain scans of people playing the ultimatum game indicate that unfair offers trigger, in the responders’ brain, a ‘moral disgust’: the anterior insula (associated with negative emotional states like disgust or anger) is more active when unfair offers are proposed (Sanfey, Rilling, Aronson, Nystrom, & Cohen, 2003). Subjects experiment this affective reaction to unfairness only when the proposer is a human being: the activation is significantly lower when the proposer is a computer. Moreover, the anterior insula activation is proportional to the degree of unfairness and correlated with the decision to reject unfair offers (Sanfey et al., 2003: 1756). Fehr and Fischbacher (2002) suggested that economic agents are inequity-averse and have prosocial preferences. Thus they modified the utility functions to account for behavioral (and now neural) data. In Moral Markets: The Critical Role of Values in the Economy, Paul Zak proposes a radically different conception of morality in economics:

The research reported in this book revealed that most economic exchange, whether with a stranger or a known individual, relies on character values such as honesty, trust, reliability, and fairness. Such values, we argue, arise in the normal course of human interactions, without overt enforcement—lawyers, judges or the
police are present in a paucity of economic transactions (...). Markets are moral in two senses. Moral behavior is necessary for exchange in moderately regulated markets, for example, to reduce cheating without exorbitant transactions costs. In addition, market exchange itself can lead to an understanding of fair-play that can build social capital in nonmarket settings. (Zak, forthcoming)

See how this claim is similar to :

The two fundamental principles of evolution are mutation and natural selection. But evolution is constructive because of cooperation. New levels of organization evolve when the competing units on the lower level begin to cooperate. Cooperation allows specialization and thereby promotes biological diversity. Cooperation is the secret behind the open-endedness of the evolutionary process. Perhaps the most remarkable aspect of evolution is its ability to generate cooperation in a competitive world. Thus, we might add "natural cooperation" as a third fundamental principle of evolution beside mutation and natural selection. (Nowak, 2006)

Hence, biological and economic theorizing followed a similar path: they started first with the assumption that agents value only their own payoff; evidence suggested then that agents behave altruistically and, finally, theoretical models were amended and now incorporate different kinds of reciprocity.

So is it good news? Are we genuinely altruistic? First a precision: there is a difference between biological and psychological altruism, and the former does not entail the latter; biological altruism is about fitness consequencences (survival and reproduction), while psychological altruism is about motivation and intentions:

Where human behaviour is concerned, the distinction between biological altruism, defined in terms of fitness consequences, and ‘real’ altruism, defined in terms of the agent's conscious intentions to help others, does make sense. (Sometimes the label ‘psychological altruism’ is used instead of ‘real’ altruism.) What is the relationship between these two concepts? They appear to be independent in both directions (...). An action performed with the conscious intention of helping another human being may not affect their biological fitness at all, so would not count as altruistic in the biological sense. Conversely, an action undertaken for purely self-interested reasons, i.e. without the conscious intention of helping another, may boost their biological fitness tremendously (Biological Altruism, Stanford Encyclopedia of Philosophy; see also a forthcoming paper by Stephen Stich and the classic Sober & Wilson 1998).

The interesting question, for many researchers, is then: what is the link between biological and psychological altruism? A common view suggests non-human animals are biological altruists, while humans are also psychological atruists. I would like argue against this sharp divide and briefly suggest three things:

1. Non-humans also display psychological altruism
2. Human altruism is strongly influenced by biological motives
3. Prosocial behavior in human and non-human animals should be understood as a single phenomena: cooperation in the economy of nature

1. Non-humans also display psychological altruism


A discussed in a previous post, a recent research paper showed that rats exhibit generalized reciprocity: rats who had previously been helped were more likely (20%) to help unknown partner than rats who had not been helped. Although the authors of the paper take a more prudent stance, I consider generalized reciprocity as psychological altruism (remember, it can be both): rats cooperate because they "feel good", and that feeling is induced by cooperation, not by a particular agent. Hence their brain value cooperation (probably thanks to hormonal mechanisms similar to ours) in itself, even if there is no direct tit-for-tat. In the same edition of PLoS biology, primatologist Frans de Waal (2007) also argue that animals show signs of psychological altruism; it it particularly clear in an experiment (Warneken et al, again, in the same journal) that show that chimpanzees are ready to help unknown humans and conspecifics (hence ruling out kin and tit-for-tat altruism), even at a cost to themselves. Here is the description of the experiments:

In the first experiment, the chimpanzee saw a person unsuccessfully reach through the bars for a stick on the other side, too far away for the person, but within reach of the ape. The chimpanzees spontaneously helped the reaching person regardless of whether this yielded a reward, or not. A similar experiment with 18-month-old children gave exactly the same outcome. Obviously, both apes and young children are willing to help, especially when they see someone struggling to reach a goal. The second experiment increased the cost of helping. The chimpanzees were still willing to help, however, even though now they had to climb up a couple of meters, and the children still helped even after obstacles had been put in their way. Rewards had been eliminated altogether this time, but this hardly seemed to matter. One could, of course, argue that chimpanzees living in a sanctuary help humans because they depend on them for food and shelter. How familiar they are with the person in question may be secondary if they simply have learned to be nice to the bipedal species that takes care of them. The third and final experiment therefore tested the apes' willingness to help each other, which, from an evolutionary perspective, is also the only situation that matters. The set-up was slightly more complex. One chimpanzee, the Observer, would watch another, its Partner, try to enter a closed room with food. The only way for the Partner to enter this room would be if a chain blocking the door were removed. This chain was beyond the Partner's control—only the Observer could untie it. Admittedly, the outcome of this particular experiment surprised even me—and I am probably the biggest believer in primate empathy and altruism. I would not have been sure what to predict given that all of the food would go to the Partner, thus creating potential envy in the Observer. Yet, the results were unequivocal: Observers removed the peg holding the chain, thus yielding their Partner access to the room with food (de Waal)

(image from Warneken et al video)

2. Human altruism is strongly influenced by biological motives

In many cases, human altruism appear as a complex version of biological altruism (see Burnham & Johnson, 2005. The Biological and Evolutionary Logic of Human Cooperation for a review). For instance, Madsen et al. (2007) showed that humans behave more altruistically toward their own kin when there is a significant genuine cost (such as muscular pain), an attitude also mirrored in study with questionnaires (Stewart-Williams 2007): when the cost of helping augments, subjects are more ready to help siblings than friends. Other studies showed that facial similarity enhances trust (DeBruine 2002). In each cases, there is a mechanism whose function is to negotiate personal investments in relationships in order to promote the copying of genes housed either in people of—or people who seems to be of—our kin.

Many of these so called altruistic behavior can be explained only by the operations of hyper-active agency detectors and a bias toward fearing other people’s judgement. When they are not being or feeling watched, peoples behave less altruistically. Many studies show that in the dictator game, a version of the ultimatum game where the responder has to accept the offer, subjects always make lower offers than in the ultimatum (Bolton, Katok, and Zwick 1998). Offers are even lower in the dictator game when donation is fully anonymous (Hoffman et al. 1994). When subjects feel watched, or think of agents, even supernatural ones, they tend to be much more altruistic. When a pair of eyes is displayed in a computer screen, almost twice as many participants transfer money in the dictator game (Haley and Fessler 2005), and people contribute 3 times more in an honesty box for coffee' when there is a pair of eyes than when there is pictures of a flower (Bateson, Nettle, and Roberts 2006). The sole fact of speaking of ghosts enchances honest behavior in a competitive taks (Bering, McLeod, and Shackelford 2005), while priming subjects with the God concept in the anonymous dictator game (Shariff and Norenzayan in press).

These reflections also applies to altruistic punishment. First, it is enhanced by an audience. (Kurzban, DeScioli, and O'Brien 2007) showed that with a dozen participants, punishment expenditure tripled. Again, appareant altruism is instrumental in personal satisfaction. Other research suggest that altruism is also an advantage in sexual selection: "people preferentially direct cooperative behavior towards more attractive members of the opposite sex. Furthermore, cooperative behavior increases the perceived attractiveness of the cooperator" (Farrelly et al., 2007).

An interesting framework to understand altruims is Hardy (no relation with me) & Van Vugt (2006) theory of competitive altruism: "individuals attempt to outcompete each other in terms of generosity. It emerges because altruism enhances the status and reputation of the giver. Status, in turn, yields benefits that would be otherwise unattainable." We need, however, a more general perspective.


3. Prosocial behavior in human and non-human animals should be understood as a single phenomena: cooperation in the economy of nature

All organic beings are striving to seize on each place in the economy of nature - (Darwin, [1859] 2003, p. 90)

With Darwin, natural economy began to be understood with the conceptual tools of political economy. The division of labor, competition (“struggle” in Darwin’s words), trading, cost, the accumulation of innovations, the emergence of complex order from unintentional individual actions, the scarcity of resources and the geometric growth of populations are ideas borrowed from Adam Smith, Thomas Malthus, David Hume and other founders of modern economics. Thus, the economy of nature ceased to be an abstract representation of the universe and became a depiction of the complex web of interactions between biological individuals, species and their environment—the subject matter of ecology. Consequently, Darwin’s main contributions are his transforming biology into a historical science—like geology—and into an economic science.

I take the economy-of-nature principle to be a refinement of the natural selection principle: while it describes general features of the biosphere, it puts emphasis on the intersection between individual biographies and natural selection, and especially on decision-making. On the one hand, the decisions biological individuals make increase or decrease their fitness, and thus good decision-makers are more likely to propagate their genes. On the other hand, natural selection is likely to favor good decision-makers and to get rid of bad decision-makers. Thus, if our best descriptive theories of animal and human economic behavior indicate that all these agents have prosocial preferences and make altruistic decisions, then these preferences and decisions are not maladaptive and irrational. They must have an evolutionary and an economic payoff. Markets and natural selections requires cooperation, even if the deep motivations are partly selfish. Fairness, equity and honesty are social goods in the economy of nature, human and non-human.

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