This new perspective owes much to the work of moral psychologist Jonathan Haidt. He has been at the forefront of research into moral decision-making, which is grounded in evolutionary theory. Because people have been living in groups for hundreds of thousands of years, it really isn’t surprising that prosocial or “moral” behaviors are often the result of intuition or snap judgments that are later explained by recourse to reason. Humans are the most prosocial of primates and it would be surprising if this ability were not highly developed.

In recent years Haidt has extended these basic insights to politics and other domains (such as religion), where the terrain is much more uneven and confounded by modern culture. The ideas, in other words, have been extended and applied in ways that are questionable. In this recent article on Haidt from The Chronicle, the overextension is apparent.

After being asked how people came together to build cooperative societies beyond kinship, Haidt asserts that “morality” was the key:

A big part of Haidt’s moral narrative is faith. He lays out the case that religion is an evolutionary adaptation for binding people into groups and enabling those units to better compete against other groups. Through faith, humans developed the “psychology of sacredness,” the notion that “some people, objects, days, words, values, and ideas are special, set apart, untouchable, and pure.” If people revere the same sacred objects, he writes, they can trust one another and cooperate toward larger goals. But morality also blinds them to arguments from beyond their group.

If we take ethnohistoric hunter-gatherers for our model of how people formed larger and more cohesive groups in the ancient past, Haidt’s “morality” answer is patently wrong. These groups were held together by kinship ties first and by extended or fictive kinship second. Their “religions” (i.e., shamanisms) weren’t grounded in morals and weren’t much concerned with morals. While such groups had moral norms and ethical rules, these weren’t twined with supernaturalism and had an independent, non-spiritual basis.

Large communities held together by religion-faith-morals are a recent development in human history, no more than a few thousand years old. The kind of community that Haidt describes is a post-Neolithic formation that has its origins in the Axial Age. So does the idea that religion is a matter of “faith.” These are not ancient or evolutionary ideas. Moralizing gods and religions are relative newcomers to the supernatural world.

Haidt’s mistake here is a common one: observe modern or relatively recent cultural formations and then uncritically project them back into the ancestral or evolutionary past. This mistake has other consequences, which are evident in what Haidt calls “innate” or evolutionary moral foundations:  “care/harm, fairness/cheating, liberty/oppression, loyalty/betrayal, authority/subversion, and sanctity/degradation.” These “innate” concerns sound suspiciously modern; I suspect at least a few are products of post-Neolithic and Western societies.

Todd Schorr's "Hunter Gatherer"

I’ve spent several years immersed in the ethnohistoric hunter-gatherer record and can’t recall much or any concern with liberty-oppression. This is the kind of concern that arises when you have centralized authority and government, which were absent for most of human history. Nor can I recall much concern for authority-subversion. Again, these kinds of concerns are related to centralized authority and government which didn’t exist in our hunting-gathering past. While hunting-gathering societies are concerned with ritual purity, translating this as sanctity-degradation has a distinctly Axial feel to it. Degradation, in particular, smacks of the Christian fall from grace.

Haidt’s “foundational morals” aren’t innate or universal. The list is provincial, limited in both time and space. Had Haidt tested his list against history or made cross-cultural comparisons, this would have been evident.

As Philip Kitcher reminds us, people can be ethical and moral without religion. From an evolutionary perspective, this makes sense. Most primates, humans included, are intensely social. It’s impossible to be social without simultaneously behaving in ways that are considered “moral” or “ethical.” This aside, there is little to no evidence that religious people in modern societies are more ethical-moral than non-religious people. Moreover, there is little to no evidence that Axial or “ethical” religions have made people or societies more ethical-moral than previous peoples. Our hunting and gathering ancestors were no more or less ethical-moral than “modern” people who have lived in settled societies during the past 10,000 years.

If Chief Rabbi Lord Sacks knew anything about evolutionary ethics and the ethnohistoric record, he wouldn’t be writing silly articles arguing that modern religions are the existential glue that hold societies together. This sort of argument is typical of apologists who believe that history and civilization essentially began with the movement toward angry gods and moralistic religions.

Elsewhere, Juliane von Mittelstaedt reports on ultra-orthodox Jewish women in Israel who cover themselves from head to toe in up to 27 layers of clothes. It is part of a larger story on the fractures these fundamentalists are creating within Israeli society, which is something that caught my attention previously in Ultra-Orthodox Slackers.

Several aspects of the Mittelstaedt story intrigue. First, it appears that most of the women wearing all these clothes have suffered serious abuse; the covering up thus seems linked to shame. Second, ultra-orthodox Jewish men in Israel routinely harangue female soldiers. This is unreal, coming from losers who are exempt from military service. This is a good time to compare and contrast.

Someone in the story astutely observes that if some of these zealots didn’t have religion as cover for their obvious madness, they would probably be institutionalized. While witnessing the antics and ideas of American evangelicals, I’ve had occasion to observe the same sort of thing.

In this mordant piece on the future of funerary, Max Rivlin-Nadler begins with the premise that the industry is in crisis because Americans are becoming more secular and fewer people are willing to pay for the bells and whistles of religious funerals. As evidence of increasing secularism, he notes that some 25% of Americans no longer claim affiliation with a church. As Rodney Stark has been saying forever, just because people don’t go to church or identify with organized religion, this doesn’t mean they are becoming secular. Most are not atheists or non-believers; they simply have alternative “spiritual” beliefs and don’t identify with institutional religion. When funeral directors realize this and begin offering non-traditional “spiritual” funerals, they will be able to tap what Rivlin-Nadlin characterizes as the “secular” market.

The authors investigated infant sensitivity to fairness and willingness to share using two experiments. In the first, infants watched a film showing someone dispensing milk and crackers to two people sitting at a table. In one scene there was a fair or equal distribution and in another the distribution was unfair or unequal. This is a standard “violation of expectations” or VOE paradigm in which infants look significantly longer at something that surprises them. The second experiment was a straightforward sharing task in infants were given two toys so they could express a preference for one. They were then asked to share a toy. The infants could choose to share the preferred toy, the other toy, or none.

In the first test, the infants looked significantly longer at the lopsided outcome. This suggests that the unfair distribution sequence violated their expectations of third-party fairness. In the second test, 68% of the infants shared at least one toy. Of these sharers, 32% shared the preferred toy and 37% shared the other toy. Remarkably, the altruistic sharers also looked at the unfair film longer than their non-sharing counterparts. Natural sharers appear to expect fairness in others and are surprised when it isn’t forthcoming.

The authors were testing the hypothesis that fairness and sharing appear early (and reliably) in development as a result of selection: “At an evolutionary level such preferences may have been crucial for our hominin ancestors to enable and maintain cooperation in small groups, and later, in larger groups of genetically unrelated individuals, to introduce norms (e.g., how to share spoils after a group hunt) that fostered group cohesion, and to motivate group members to enforce those norms.” These traits, in other words, would have been adaptive in both ancestral and later environments.

These findings support the hypothesis. By 15 months of age, infants have at least a rudimentary sense of fairness and expect resources to be shared equally. A basic sense of altruism is already prevalent at this early stage of development. This suggests to the authors that “infants evaluate events along morally relevant dimensions” before they receive cultural training reinforcing these tendencies.

Infants are not little devils and indeed appear to be part angel. But as all parents know, they can be a bit of both at times. Because neither purity nor impurity accurately describes infants, the best representation might be this:

Reference:

Schmidt, Marco, & Sommerville, Jessica (2011). Fairness Expectations and Altruistic Sharing in 15-Month-Old Human Infants PLoS ONE, 6 (10) DOI: 10.1371/journal.pone.0023223

Whereas human pro-social behavior is often driven by empathic concern for another, it is unclear whether nonprimate mammals experience a similar motivational state. To test for empathically motivated pro-social behavior in rodents, we placed a free rat in an arena with a cagemate trapped in a restrainer. After several sessions, the free rat learned to intentionally and quickly open the restrainer and free the cagemate. Rats did not open empty or object-containing restrainers. They freed cagemates even when social contact was prevented. When liberating a cagemate was pitted against chocolate contained within a second restrainer, rats opened both restrainers and typically shared the chocolate. Thus, rats behave pro-socially in response to a conspecific’s distress, providing strong evidence for biological roots of empathically motivated helping behavior.

It may seem gratuitous to point out that rats don’t have religion and I do so only because evolutionary theists often argue that religion evolved because it makes people cooperative and altruistic. Religion, in their view, is an evolutionary adaptation targeted by natural selection because it creates or enhances empathy and pro-sociality.

Those who make this argument usually ignore the fact that empathy, cooperation, and altruism are widespread in nature. Non-human primates are intensely social and quite cooperative, as are elephants and dolphins. Now we can add rats to the list. Religion isn’t necessary to explain these behaviors.

When confronted with these facts, evolutionary theists usually resort to one of two arguments. The first is that religion makes people more empathetic and pro-social than they would otherwise be without religion. While this may true of post-Neolithic religions which first linked supernatural beliefs to “moral” behaviors, this relatively recent development says nothing about the evolutionary origins of religion.

The second argument is that religion would have made human groups more cohesive and given them a competitive advantage over other groups. While it may be true that post-Neolithic religions functioned as ideological glue for larger groups (group size being the most important predictor of group level success), there is no evidence that human group sizes increased until after the domestication of plants-animals approximately 12,000 years ago. Again, this relatively recent development says nothing about the evolutionary origins of religion.

Speaking of group size, if you are considering rats as pets — something I recommend — remember they are social and you will need to get at least 2 and preferably 3 or  more, all of the same sex (unless you want lots of babies, which I don’t recommend). For reasons that weren’t clear to me until yesterday, I’ve always had females. The study found that females are slightly more empathetic and pro-social than males.

Reference:

Bartal, I., Decety, J., & Mason, P. (2011). Empathy and Pro-Social Behavior in Rats Science, 334 (6061), 1427-1430 DOI: 10.1126/science.1210789

Until recently, I hadn’t given much thought to promises per se or their critical importance to the evolution of conscience. Nietzsche, not surprisingly, understood its importance and addressed the issue in Genealogy of Morals (II:1): “To breed an animal with the right to make promises — is not this the paradoxical task that nature has set for itself in the case of man?” 

In Making Sense of Nietzsche, Richard Schacht highlights the importance of this question — and its answer:

What engages his attention here is the fundamental issue of what the possibility of promising (and keeping one’s promises) presupposes, and the ramifications in human life in the establishment of this possibility. Its establishment, Nietzsche contends, required the development of a kind of memory going beyond the (basically animal) capacity to absorb and retain things experienced.

This immediately calls to mind chimpanzees. Many have observed they are always “in the present,” trapped as it were by memories that can only be cued by external events or environments. The ability to self-cue memories without such prompts — to cease being creatures of the moment — was a fundamental cognitive shift or what I would call a phase change involving consciousness. By this view, which makes considerable transcend-sense, promissory ability is the prerequisite for “moral” ability.

Because stress, abuse, neglect, and illness are fairly good descriptors of the human condition, all that natural goodness is rarely expressed. It might be more accurate to say if we could eliminate stress, abuse, neglect, and illness, people would be nicer and more cooperative. This is either stating the obvious or a tautology; I’m not sure which.

These ostensibly disparate movements had much in common. Suffering and death are central concerns. Given these concerns, it is not surprising that all devise methods for transcending suffering and death. Such transcendence, whether in this world or life or the next, becomes an ethical matter and moral issue.

Why did these related ideas appear in several places in such short order? Because these traditions arose in widely disparate places and originated among people who were not in contact with one another, we know it was not a matter of cultural diffusion or idea migration. There are several competing (and complementary) hypotheses, most of which revolve around change, dislocation, and anomie.

The few thousands of years preceding the Axial Age were an especially turbulent time in human history; warfare, urbanization, disease, and famine were operating full-tilt and on a scale never before seen. People everywhere were at a loss and legitimacy was in short supply. Under such conditions, it would be surprising if something like the Axial movements did not appear. During times of immense and protracted crisis, intellectuals will often generate new and paradigm shifting ideas.

But before such breakthroughs can occur, the ground must be prepared. Although Axial movements were innovative, they did not simply appear sua sponte. To the extent they were reformist or reactionary, they were backward looking and dependent on the past for comparative appeal. In “Ancient Mesopotamian Religion: The Central Concerns,” renowned ancient historian Thorkild Jacobsen summarizes that past by dividing it into three thematic and millennial epochs:

Fourth Millennium BCE — Famine

“Give Us This Day Our Daily Bread”

The fear at the very roots of existence that long ago, down through the fourth millennium, gave to the religious response in Mesopotamia its major direction would seem to have been a simple one: fear of starvation. Early Mesopotamian economy was unquestionably a remarkable achievement, able for the first time to provide sufficient food so that large numbers of humans could congregate in cities. But it was also a precarious and uncertain economy, for it was based on artificial irrigation, the most touchy and tricky basis imaginable, nervously reacting to vagaries of nature and man alike.

And the character of their religion as we know it bears this out. The powers to whom they turned were powers in and behind their primary economics on which life depended: fishing, herding, agriculture, as even the briefest look at the character of the chief gods of their cities will show. [T]heir cults were to insure the presence of these essential powers for fertility, produce, and food.

Third Millenium BCE — War

“Preserve Us From Evil”

As the settled areas of the country grew and joined, the protection that had been afforded by relative isolation was no longer there and fear of enemy attack, death or slavery, became a part of life ever present in the depth of consciousness. The intensity of the danger and of the fear it engendered can be gauged by the great city-walls that arose around the towns in this period and the staggering amount of labor that must have gone into them.

For a shield against danger men looked to the now vitally important institutions of collective security, the great leagues and their officers, and particularly to the new institution of kingship as it took form and grew under the pressures of these years. The new concept opening up, as it did, a possibility of approach to the element of majesty in the divine, was early applied to the gods and it profoundly influenced the religious outlook. The gods, seen as kings and rulers, were no longer powers in nature only, they became powers in human affairs — in history.

Second Millennium BCE — Guilt

“Forgive Us Our Trespasses”

[W]ith the beginning second millennium the personal fortunes of the individual worshiper, his fears of personal misfortune, anxieties in illness and suffering, begin to be voiced adding a personal dimension to the relation with the divine. [Because of famine and war, it appears this personal] god has abandoned the worshiper and lost interest in him. He realizes that the blame lies with himself-pleading, however, that no man is perfect and asks to be shown his faults, his transgressions, that he may confess them before his god and be forgiven. And the god is moved by his contrition and takes him back into favor.

There is here the beginnings of a searching of the heart: the insight gained in the preceding millennium that the divine stands for, and upholds, a moral law is now bearing fruit in a realization of individual human responsibility, but also of innate human inability to live up to that responsibility. [T]he question of man’s acceptability before his god — the problem of the righteous sufferer — led on to realization of man’s finiteness and the altogether finite character of his insights and his moral judgments.

During the first millennium BCE Mesopotamian religions stagnated, perhaps because for thousands of years they had always been concerned with that which was immanent or present in this world. If the divine was present in the world, few (other than the rich and powerful) seemed to be feeling it. It was time for something new. The stage was thus set for Axial transcendence.

References:

Strathern, Alan (2009). Karen Armstrong’s Axial Age: Origins and Ethics The Heythrop Journal, 50 (2), 293-299 DOI: 10.1111/j.1468-2265.2009.00413.x

Jacobsen, Thorkild (1963). Ancient Mesopotamian Religion: The Central Concerns Proceedings of the American Philosophical Society, 107 (6), 473-484

I was reminded of Horace’s enduring wisdom by two recent studies; the first on cooperation and second on punishment. Both are major contributions to our understanding of human altruism and collective action. Neither invokes the magic of gods.

In the “Evolution of Direct Reciprocity,” Andrew Delton and colleagues demonstrate that humans are naturally generous even to strangers and that such generosity is evolutionarily advantageous. A co-author of the July 25 PNAS study, Leda Cosmides, explains why humans can afford to be generous (i.e., incur costs) even when interaction might be a one-time affair:

There are two errors a cooperating animal can make, and one is more costly than the other. Believing that you will never meet this individual again, you might choose to benefit yourself at his expense –– only to find out later that the relationship could have been open-ended. If you make this error, you lose out on all the benefits you might have had from a long-term, perhaps life-long, cooperative relationship. This is an extraordinarily costly error to make.

The other error is to mistakenly assume that you will have additional interactions with the other individual and therefore cooperate with him, only to find out later that it wasn’t necessary. Although you were “unnecessarily” nice in that one interaction, the cost of this error is relatively small. Without knowing why, the mind is skewed to be generous to make sure we find and cement all those valuable, long-term relationships.

This is the restrained and mathematical kind of evolutionary psychology we can believe in.

In “Punishment Sustains Large-Scale Cooperation in Prestate Warfare,” Sarah Mathew and Robert Boyd find that profane punishment solves the free-rider problem that so exorcizes some evolutionary theorists of religion:

Understanding cooperation and punishment in small-scale societies is crucial for explaining the origins of human cooperation. We studied warfare among the Turkana, a politically uncentralized, egalitarian, nomadic pastoral society in East Africa.

Based on a representative sample of 88 recent raids, we show that the Turkana sustain costly cooperation in combat at a remarkably large scale, at least in part, through punishment of free-riders. Raiding parties comprised several hundred warriors and participants are not kin or day-to-day interactants. Warriors incur substantial risk of death and produce collective benefits. Cowardice and desertions occur, and are punished by community-imposed sanctions, including collective corporal punishment and fines. Furthermore, Turkana norms governing warfare benefit the ethnolinguistic group, a population of a half-million people, at the expense of smaller social groupings.

These results challenge current views that punishment is unimportant in small-scale societies and that human cooperation evolved in small groups of kin and familiar individuals. Instead, these results suggest that cooperation at the larger scale of ethnolinguistic units enforced by third-party sanctions could have a deep evolutionary history in the human species.

Large-scale cooperation, in other words, can revolve around something other than systematic religion or supernatural punishment. Shared language and ethnicity — along with earthly rewards (and beatings) — seem to work just fine.

We don’t need a group level or adaptive deus ex machina to explain the extraordinary success of ordinary humans. Parsimony to the rescue.

References:

Delton AW, Krasnow MM, Cosmides L, & Tooby J (2011). Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters. Proceedings of the National Academy of Sciences of the United States of America PMID: 21788489

Mathew S, & Boyd R (2011). Punishment sustains large-scale cooperation in prestate warfare. Proceedings of the National Academy of Sciences of the United States of America, 108 (28), 11375-80 PMID: 21670285

Source: John Young, UK (Creative Commons)

That’s balut, a dish of southeastern Asia. It’s made by boiling a fertilized duck egg. If you’re like me—an American raised on hamburgers and chicken casseroles—your first reaction on seeing balut might not be to salivate. In fact, you might feel disgust. But to people in many cultures, balut is delicious.

Disgust is a powerful emotion that serves a protective purpose. It is closely related to our fear of contagion and has been subject to intense evolutionary selection pressure. This is why we’re disgusted by things that might make us sick, such as rotten food and filth. We are less likely to get sick if we avoid things we find disgusting.

But what disgusts us is also subject to our cultural environment. We’re more likely to find familiar foods delicious and unfamiliar foods disgusting, which is why your reaction to the balut pictured above was probably different depending on whether it’s something you’ve eaten a hundred times before or something totally new.

Disgust is not, however, limited to biological domains: aversion spills over into other aspects of our lives. It is but a short symbolic step from intuitive microbiology (“Gross, don’t touch that!”) to moral intuition (“Gross, don’t do that!”). This explains why we find violations of moral rules, such as unfair division of money, disgusting.

Just as our tastes in food vary across cultures, our moral “tastes” vary in the same way. A recent study suggests that we can feel disgust not only for others’ foods and behaviors, but for their beliefs as well.

In the lab where I work, Ryan Ritter and Jesse Preston studied “belief disgust” using a novel experimental method. Under the guise of a consumer marketing survey, participants drank what they thought were two slightly different versions of a beverage—really the same drink each time, an especially sour lemonade. After tasting each beverage, participants gave their reactions to it, rating how sour, sweet, bitter, delicious, and disgusting it was. In between drinks, supposedly to give them time to cleanse their palates, participants completed a handwriting task. And this is where it gets interesting.

For the handwriting task, each participant copied a passage from one of three texts: The Merriam-Webster Dictionary, the Qur’an, or Richard Dawkins’s The God Delusion. Because all the participants were Christian, the second two passages (Qur’an and Dawkins) are strong endorsements of ideas antithetical to their own beliefs. The dictionary passage, in contrast, is neutral with respect to their religious beliefs.

The researchers wanted to know if Christians would feel more disgust after reading the outgroup passages than the neutral passage. This is where the beverage tasting is important. If participants rated the second beverage as more or less disgusting than the first, this would be evidence that the passage affected feelings of disgust (since the beverages were identical).

In the Dawkins and Qur’an conditions, participants rated the second drink as more disgusting than the first. In the dictionary condition, however, the second drink was actually rated as slightly less disgusting than the first.

In a second experiment, when participants were given a chance to clean their hands (with a wipe) after using them to write the outgroup texts, there was no difference in disgust between the two drinks. This experiment also used a Bible passage instead of the dictionary passage. Without the hand cleaning, there was no difference between the drinks; however, when participants cleaned their hands after writing the Bible passage, the second drink was actually less disgusting than the first.

From a research perspective, these are exciting results. They show that foreign ideas can trigger the powerful (and largely subconscious) emotion of disgust. They also suggest that moral disgust can be alleviated or “purified” by simple acts such as handwashing. This may speak to the origin of certain rituals, many of them religious.

From a personal perspective, these results are disconcerting. If our intuitive response to outgroup beliefs is disgust (a powerful moral emotion), reducing prejudice and increasing cooperation between groups seems a difficult task.

Then, again, maybe this is good news. Now that we know more about causes of cultural conflict, we may be able to use this knowledge to design interventions with the goal of reducing intuitive (or irrational) disgust responses. After all, if we can learn to eat the foods of other cultures, could we not also learn to “digest” their ideas?

– Guest Post by Erika Salomon, A Theory of Mind

Reference:

Ritter, Ryan, & Preston, Jesse Lee (2011). Gross gods and icky atheism: Disgust responses to rejected religious beliefs. Journal of Experimental Social Psychology : 10.1016/j.jesp.2011.05.006

Jeff Schloss and Michael Murray have written a “target article” in Religion, Brain & Behavior entitled: “Evolutionary Accounts of Belief in Supernatural Punishment: A Critical Review”. Schloss and Murray’s argument is as follows. In recent years a wide range of adaptationist, byproduct, and memetic explanations has emerged for various recurrent features of religious belief and practice. One feature that has figured prominently in adaptationist accounts of religion is belief in the reality of moralizing, punishing supernatural agents.

However, there is at present no unified theory of what fitness-relevant feature of the selective environment this cognitive predisposition is adapted to. Schloss and Murray distinguish two divergent and often conflated approaches to supernatural punishment theory, which hypothesize that the adaptive value of beliefs in supernatural punishment arise either because they increase cooperation among group members (”cooperation enhancement”), or decrease the cost of incurring (real world) punishment for norm violations (”punishment avoidance”).

Although a number of scholars have provided comments to the Schloss and Murray article, Rodney Stark does not appear to be one of them. This is most unfortunate, given that Stark has written a classic article — “Gods, Rituals, and the Moral Order” — which directly addresses these issues and tests them with actual religious history (rather than abstract game theory).

Of supreme importance is the fact that “punishing, moralizing supernatural agents” (or gods) appear in very few religions, and those few in which they do appear are relative latecomers in religious history. Indeed, a strong argument can be made that a robust punishing, moralizing god originated with Judaism and is primarily associated with the Abrahamic faiths. Punishing and moralizing supernatural agents certainly are not associated with the many forms of shamanism that constituted the original “religions” of Upper Paleolithic humans.

If this is the case, it makes little sense to hypothesize about the “adaptive value” of the punishing and moralizing God of Judaism, Christianity, Islam, and successor sects such as Mormons and Jehovah’s Witness. While this localized and modern conception of God may make Jews, Christians, and Muslims more “cooperative” and “moral,” this says nothing about human evolution or the origins of “religion.”

Framing the issue in this way makes about as much sense as asking how the cognitive predisposition for nationalism (another late development in human history) is adaptive. I am not aware of any scholars who analyze nationalism by asking “what fitness-relevant feature of the selective environment it is adapted to.” Why? Because biological evolutionary mechanisms have minimal explanatory power in modern cultural and historical settings.

The adaptationist yearning for a “unified theory” results in an erroneous conflation of biological evolution with cultural history. The tools of the former are ill adapted to analysis of the latter.

While lab experiments may show that supernatural surveillance impacts behavior, this is precisely what one would expect in Western cultures permeated with the idea that God punishes moral transgressions. Such experiments tell us nothing about the evolution of cooperation or religion.

Reference:

Stark, R. (2001). Gods, Rituals, and the Moral Order Journal for the Scientific Study of Religion, 40 (4), 619-636 DOI: 10.1111/0021-8294.00081