Altruistically Inclined? The Behavioral Sciences, Evolutionary Theory, and the Origins of Reciprocity

Published by EH.NET (June 2002)

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Alexander J. Field, Altruistically Inclined? The Behavioral Sciences, Evolutionary Theory, and the Origins of Reciprocity. Ann Arbor: University of Michigan Press, 2002. xvi + 373 pp. $54.50 (cloth), ISBN: 0-472-11224-4.

Reviewed for EH.NET by Rick Szostak, Department of Economics, University of Alberta.

Alexander Field (of Santa Clara University) makes a number of key points in this book: –The human mind is “modular”; if we use a computer analogy we should think of it as a loosely coordinated set of distinct programs rather than one master program.

–While we might have been selected to behave in a selfish rational manner in some circumstances we might also have been selected to behave altruistically.

–Observation of seemingly rational and selfish behavior over some range of situations should not lead us to conclude that altruism is not an important human impulse.

–There is in fact abundant evidence from a range of fields that (most) humans do have altruistic predispositions.

–The word altruism is often defined ambiguously. An evolutionary perspective allows a precise definition of altruism as behavior that decreases an organism’s reproductive fitness while enhancing the fitness of others.

–Many important human behaviors (including voting behavior, and less ‘free riding’ than theory predicts) cannot be comprehended without reference to altruism.

–Of special note for economists, strategic behavior is conditioned by altruism. Models without a place for altruism thus make the wrong predictions.

–Social scientists are hesitant to accept the existence of altruism — despite abundant evidence — in large part because we lack a compelling account of how this could have been selected for.

–Moreover our understanding of the precise nature of our altruistic tendencies could be informed by an understanding of how these were selected for.

–Students of evolution have struggled to explain how altruism could have been selected for. Many, if not all, of the explanations proffered fail to deal with the question of origins. “Reciprocal altruism,” for example, which suggests that we benefit more from the altruism of others than we suffer from our own, fails to explain why the first human predisposed to altruism would not have been harshly selected against.

–New models of ‘group selection’ have now been accepted by many scholars of evolution, and these provide a new evolutionary argument for altruism.

Field has read widely across many disciplines. Most of the points above are widely accepted by the relevant communities of scholars. While economic theory conceives of humans as having one master program, modularity is now accepted not just by evolutionary scholars but by psychologists more broadly. The last two points, regarding how altruism might have been selected for, are more controversial, and I will discuss these in more detail below.

Field is to be applauded for synthesizing this vast and diverse literature and pointing out its implications for the practice of economics. Field writes clearly (albeit, as he himself confesses, with a bit of redundancy): economists with no previous exposure to evolutionary theory, psychology, neurophysiology, paleontology, or a range of other disciplines will gain a valuable appreciation of what these scholars have to tell us about human behavior.

Much of the book is devoted to a discussion of strategic behavior. In one-time Prisoner’s Dilemma games, we expect players to defect, but commonly observe that they cooperate. If we rely on selfish rationality, we cannot explain the observed behavior in situations where there are no future repercussions of selfish behavior. If we recognize that humans have some predisposition toward altruism, though, then we can readily explain cooperation.

We all appreciate that society as a whole will benefit if humans are predisposed to cooperate rather than defect in Prisoner’s Dilemma situations: the total ‘payoff’ is higher when we cooperate. Once some predilection toward altruism became established in a group of humans, then, we can readily imagine continued selection in its favor. That is, arguments from ‘reciprocal altruism’ then kick in. The problem, as noted earlier, is to explain how altruism could first become established within any human group.

Nor is the Prisoner’s Dilemma an isolated scholarly curiosity. Field discusses many instances where a misguided appreciation of human motivations led to misguided policy proposals. Notably, both von Neumann and Bertrand Russell (a pacifist by nature) applied a selfish view of human nature to the Cold War. Perceiving the nuclear standoff as a Prisoner’s Dilemma game, they advocated a first strike against the Soviet Union. As Field notes, not only were they wrong in assuming that “defection” was inevitable, but they were likely wrong in assuming that a defeated enemy would not bother retaliating: our sense of “fairness” is related to our altruism, and might well guide retaliation even if we could not benefit from this. Indeed we can expect that a propensity to retaliate for perceived violations of ‘fair play’ — and also specialized abilities to detect ‘cheaters’ — would have been selected for once a predisposition toward fairness itself had been selected for. Social scientists tend to explain any observed case of ‘restraint’ as the result of either norms or a mutual recognition of the benefits of restraint; we should appreciate that we may be ‘programmed’ for (altruism, fairness, retaliation, and thus) restraint.

Field also discusses finite repeated games at great length. As we know, the “selfish rational” strategy is to defect in the last round. Given this, we should also defect in the second last round, for we should presume that our opponent will also defect in the last round, and thus we gain no benefit from trying to encourage cooperation in the previous round. The same logic can be applied to all previous rounds, leading to a prediction of defection from the outset. Field gleefully reports an early experiment in which the economist Armen Alchian was pitted against noted mathematician John Williams in a 100-round Prisoner’s Dilemma game. Alchian defected at first, but Williams did not. Alchian at first thought that Williams was irrational, but soon joined him in cooperating, and they cooperated for the most part until the later rounds. John Nash, when informed of this outcome, complained that he would have expected the players to behave more rationally. Of course, the payoff each received during the game was greater than if they had “rationally” defected each time. And thus I am not so sure that even the truly selfish would not think it worthwhile to gamble on cooperation at some early stage of the game. But Field argues, and Nash and many other game theorists would concur, that the selfishly rational should always defect, and thus the superior strategy of cooperating will only be observed if the players have some predisposition toward altruism (and expectation that others are similarly disposed).

Teaching our students only about selfish rationality guides them to emphasize this ‘program’ over their altruistic impulses. Appreciating altruism at the expense of ignoring our selfish impulses would also be inadvisable. We should appreciate that we each possess conflicting impulses, and moreover that we differ in the relative strength of these due both to differences in genes and environment.

No science should jettison a valued theory at the first sign of dis-confirming evidence. But when evidence mounts that humans are not always strictly selfishly rational, a science should seek to identify the range of applicability of its theory. Field argues that market exchange largely mimics the foraging (for food) behavior of our distant ancestors. If our ancestors were selected to be selfishly rational in foraging, then we will observe selfish rationality in market exchange (except when issues of strategic behavior or fairness arise). We need not abandon our models of market exchange, then, but should be wary of extending these into areas, such as strategic interaction, in which non-selfish motives may have an important role to play.

Scientists are attracted by simplicity, and the dream of one simple theory that can explain all will die hard. Moreover, as Field notes, rational choice theory has an aesthetic appeal [a point I have made in my Econ-Art: Divorcing Art from Science in Modern Economics; London: Pluto, 1999]. Field, by suggesting realms in which selfish rationality may dominate, and others where it does not, identifies a path forward for the economics discipline. We can become more broadminded, while not being forced to jettison that which we have developed heretofore. We can apply rational choice theory as appropriate, and cease trying to ‘rescue’ rational choice theory at any cost as an explanation of everything. In order to be theoretically flexible, though, we may also have to be methodologically flexible; alternatives to rational choice may not be susceptible to maximization or even formalism, and we will have to supplement statistical analysis with experiment and observation.

While we generally conceive of altruism in terms of acts of kindness, Field urges us to also recognize altruism in those much more common situations where we do not harm others for personal gain. We all undoubtedly face numerous opportunities in our lives to do so, and forsake these in a manner inconsistent with selfish rationality (though I think that in some of the examples Field provides even the selfish might avoid striking first from fear of (even ‘rational’) retaliation). Field suggests that our modern world, in which we regularly interact with strangers, would be impossible, or at least much less productive, if we could not assume that these strangers would not seize every opportunity to benefit at our expense. Altruism, then, is an essential element of modern complex societies.

Field’s fourth chapter addresses the work of Robert Frank. Frank is applauded for showing through a variety of experiments that humans both display and detect emotions, and that these predispositions have important implications for human — and particularly economic — behavior. Frank’s key point is that while emotions may seem ‘irrational’, they in fact help us to make credible commitments and thus can be beneficial. Field notes here that within standard game theory we should be extremely skeptical of ‘reputations’ because the selfishly rational will betray their reputation when it suits them; display of emotions allows us to communicate that a particular reputation reflects a personal predisposition to behave in a certain manner. Field is critical of Frank’s failure to define “rational” carefully, arguing that this is best done in terms of genetic fitness. But Field’s greatest concern is that Frank fails to show how the genetic predispositions he speaks of could have been selected for in the first instance; as with altruism itself the first to display emotion should have been at a disadvantage.

Field’s sixth chapter addresses the Prospect Theory or ‘framing’ literature associated with Kahneman and Tversky. Field applauds these authors for showing that humans are not strictly rational: the way that problems are framed influences the solutions that agents choose. Field is critical, though, of the huge and often conflicting variety of biases in decision-making identified by the research program. Field argues that we would have been selected to solve problems commonly faced by distant ancestors. Evolutionary theory can thus guide us to testable conjectures on what sorts of problems we should be good at solving, and how novel problems will be framed in terms of ancestral problems (though once we accept modularity we must also accept the possibility of conflicting biases). In particular, since our distant ancestors would have faced few truly random processes, we may be ‘programmed’ to look for duration dependence in casinos or stock markets. While Field is correct to suggest that evolutionary theory can help us to organize and discriminate among this growing literature, I thought he was a bit too dismissive of its accomplishments. Science advances through the interaction of deduction and induction: we should rely neither on just deduction from evolutionary theory nor induction from diverse observations of seemingly irrational behavior.

While Field largely speaks to economists he also argues that other social sciences need to ground their theories in a more nuanced understanding of human nature. Anthropologists and sociologists have tended to assume that the mind is a blank slate (tabula rasa) on which any culture can be written. If, though, we were all selected for a certain set of genetic predispositions, these likely place limits on the range of cultural variability. Students of culture, then, should strive to explain where values come from, and particularly how they reflect basic human nature. Having made similar arguments of late myself, I wholeheartedly concur.

Field only occasionally addresses economic history directly. He argues that economic historians, like all other scientists, need to understand the complexity of human nature. We need to understand how culture and institutions reflect human nature, and how these in turn affect behavior. He notes that the uniqueness of historical events limits our ability to predict. We should thus break complex historical events into their constituent parts — the causal relationships among key variables involved — and then seek comparisons of causal linkages across diverse times and places. This is an approach to economic history, and science more generally, that I have also embraced in recent work.

As noted above, the most controversial part of Field’s project is the contention that only the latest versions of group selection theories of evolution can explain how altruism (or fairness, or emotion) was first selected for. These theories note that a genetic tendency that is selected against at the level of the organism may nevertheless increase in prevalence in the population as a whole if the group(s) in which the tendency occurs grow more rapidly than others. The theories rely on occasional regrouping of the population so that genes are transmitted among groups; given that breeding across groups seems to have characterized ancient humanoid populations, this is likely a reasonable assumption. Even if altruistic individuals are selected against within their groups, growth in the size of these groups, and transmission of altruistic ‘genes’ across group boundaries, can result in the predisposition toward altruism increasing in prevalence in the global population. As noted above, once ‘enough’ individuals are altruistically inclined, the ‘reciprocal altruism’ arguments favored by Frank and others will add additional selection pressure for altruism.

Field defines altruism as behavior which reduces an organism’s reproductive fitness but enhances the fitness of other organisms. We can presume that the benefit must outweigh the cost, or no sort of selection for the trait could occur. And thus it is straightforward that any group possessing an altruist will grow faster than a group without (assuming that most or all altruistic acts are directed toward those one regularly interacts with).

But the group selection mechanism can only work if the rate at which altruistic organisms are selected against within the group is less than the rate at which the group(s) possessing altruists grows (relative to the population). Field does not emphasize this simple fact, and writes as if the ‘theory of group selection’ on its own solves the ‘problem of origin.’ But this result cannot be assumed. Indeed, if the growth in the group entirely reflects the benefits to other organisms of interacting with altruists, then the rate of group growth must be less than the rate at which altruistically inclined organisms are selected against within the group. Altruists have fewer heirs than they would have had if non-altruistic, while non-altruists in their group will have more.

Somehow, organisms that embody a propensity to altruism must benefit from the growth in their groups, if group selection is to work. In other words, they must gain some indirect benefits that outweigh the direct costs of altruism. But then it is not clear that we are talking about altruism as Field defines it any more, for it turns out that behaving altruistically does not reduce fitness (on average) after all.

Field warns us to distinguish between fitness at the level of the gene and fitness at the level of the organism. Of course, altruism has to somehow be fitness-enhancing at the level of the gene if it is to spread. But his argument is focused at the level of organisms. However, since genes are necessarily embodied in organisms, the only way to distinguish fitness at the two levels is this: one can argue that an altruistic act enhances the fitness of other organisms carrying a genetic predisposition to altruism more than it reduces the fitness of the organism behaving altruistically. But this line of argument resembles ‘reciprocal altruism’ and as Field stresses at many points reciprocal altruism begs the question of how we first get ‘enough’ altruistically inclined individuals for the benefits to outweigh the costs.

One possibility would be to suggest that one is likely to be most altruistic toward one’s family. One might thus have fewer children than otherwise, but will greatly enhance the fitness of those one does have. But this is a kin selection argument. Kin selection likely works to explain how we could have been selected to make sacrifices for close relatives. But genes that predispose us to be nice just to kin should have an advantage over those that predispose us to be indiscriminately nice. Kin selection explanations of altruism have been around for years, but have received little support. Does group selection make this story more compelling? Perhaps. But since this line of argument is at best implicit in Field’s book, the book can provide little insight on this key point. And note again that the key to this kin selection mechanism is the benefits that altruists bestow on other altruists; if we believe these to be large enough to outweigh the costs to the original altruist we do not need group selection arguments at all. In other words, the benefits bestowed on non-altruists are not at all important for our story: all that matters is that altruists themselves benefit more than they suffer.

If we want to make non-altruists a part of our story we need to say how altruists benefit indirectly from the fitness-enhancement they give to the non-altruists in their groups. Perhaps the growth in the group will give the altruistically inclined more potential mates, and may increase average survival chances if the benefits of size outweigh the disadvantages associated with pressure on resources. While their fitness is enhanced less than the non-altruists with which they interact, the altruists might also thus see some increase in fitness. Or perhaps (some of) the benefits to the group flow from direct competition with other groups. If so, we need to specify how having one altruist benefits the group (beyond just making the group bigger). The most obvious scenario has the altruist(s) leading the attack; it is hard to see how the benefit to the group would not be swamped by the reduced fitness of altruistic organisms in this case. Or maybe, in a twist on Hobbes, the group self-interestedly elevates the altruistic individual to a leadership position, for the altruist is better able to motivate group action (because not subject to as much suspicion). This, though, would be better characterized as selection at the level of the individual. But these are just speculations by this reviewer; the question of how the altruistic might benefit indirectly from their altruism toward non-altruists is not addressed by Field.

If we accept that altruism is (indirectly) fitness enhancing at the level of the individual we might be guided to appreciate that group members play a variety of non-Prisoners Dilemma games with each other. Mating and hunting are two obvious cases where the choice of cooperation benefits both. Indeed, how could we have groups before the emergence of altruism if such games weren’t common? By occasionally altruistically helping others I regularly interact with I may benefit even if they never respond altruistically, simply because I enhance their ability to self-interestedly interact with me in the future.

Haim Ofek, in Second Nature: Economic Origins of Human Evolution (Cambridge University Press, 2001; see my forthcoming review in the Journal of Economic Literature), argues that humans were selected for exchange, and that both the harnessing of fire, and the development of a hunter-gatherer lifestyle, were dependent on a previous selection for exchange. Among the components he suggests for our exchange ‘module’ is some level of ‘trust’. We cannot trade if we expect the worst from everyone. Ofek does not pursue the ‘trust’ angle. But if he is right that we were selected for exchange, then we could imagine that altruists might have had an advantage as traders, for they would have been viewed as more trustworthy by others. If so, selection for some degree of altruism (and fairness and display of emotion) would be straightforward.

While I wish that Field had fleshed out his group selection story in more detail, I still recommend this book highly. It provides a handy guide to a diverse literature that should interest all economists and historians. Field shows how we can and should embrace a more nuanced understanding of human nature. His book should inspire a greater flexibility in both the theories and methods of the economics discipline. Economic history can and should show the way.

Rick Szostak is Professor of Economics at the University of Alberta. His research spans economic history, methodology, and the theory and practice of interdisciplinarity. His fifth book A Schema for Unifying Human Science: Interdisciplinary Perspectives on Culture (forthcoming, 2002) shows how the study of individual causal links can be organized into a coherent whole. He has recently finished a manuscript Classifying Science: Phenomena, Data, Theory, Method, Scientific Practice, which develops classifications of these various elements of science, and discusses at length the strengths and weaknesses of different methods and types of theory, as well as how various biases and errors affect different types of science. A paper drawing on these insights, “Economic History as It Is and Should Be,” will be presented at the International Economic History Association conference in Buenos Aires.