Why Do We Rape, Kill and Sleep Around?

The "new" Newsweek is running an article on the evolutionary psychology debate that seems heavily slanted to one side. There seem to be some confusions in the article. They leave a bad impression of its objectivity.

Why Do We Rape, Kill and Sleep Around?

Over the years these arguments have attracted legions of critics who thought the science was weak and the message (what philosopher David Buller of Northern Illinois University called "a get-out-of-jail-free card" for heinous behavior) pernicious. But the reaction to the rape book was of a whole different order. Biologist Joan Roughgarden of Stanford University called it "the latest 'evolution made me do it' excuse for criminal behavior from evolutionary psychologists." Feminists, sex-crime prosecutors and social scientists denounced it at rallies, on television and in the press.

Such commentary is entirely political and nonscientific. It hardly merits a moment's response. Of course heinous behavior is not justified even by facts that are beyond dispute. The fact that humans have hands and arms that can wield weapons, or can even kill with bare hands, does not excuse murder. Likewise, behavioral traits that can be explained by evolution do not excuse rape and killing. (As for "sleeping around", that is in a different moral category entirely, if in any moral category at all.) Nothing more needs to be said about this kind of inanity that the article offers up.

So on to more substantive issues.

Scientific objectivity tends to be the victim of its own special kind of rape when "philosophers" enter the scene. Too bad "philosophers" don't stick to their own business and limit the damage to their own ranks. Philosophers (and their even more badly behaved kin, the "theologians") have certainly left enough carnage in other scientific topics, such as embryonic stem cells.

But read the article yourself, and then consider its shortcomings.

Exactly how was it decided that "evolutionary psychology" and "mental modules" are coextensive hypotheses? It seems to me that EP could easily be valid without the stronger hypothesis of modules. Who is it that's insisting the two ideas are inseparable?

Same question regarding "universal human nature". EP can easily explain traits that have context-dependent behavioral expression. Likewise, why does "universal human nature" have to be taken to rule out context-dependency of behavior?

Clearly, brain organization is very complex. From a programming perspective, it would be expected to involve a lot of conditional logic. Evolution nevertheless produced the organization the brain has now. Why would that be limited to only the most simplistic forms of organization - straight-line coding that has no alternative paths and data dependencies?

How hard is it to imagine that certain traits evolved in older stages of the human brain (or pre-human brain, for that matter), but that these traits have been partly been modified in later stages, with override switches when appropriate?

A nebulous "flexibility" is itself a debatable hypothesis, and it smells of the vacuousness that EP is accused of. It needs its own scientific evidence before being accepted. New social and physical conditions (for example, very high population densities, unlike any that humans have experienced over multiple generations) may require further evolutionary reprogramming when the supposed flexibility can't handle the changes.

Are straw man arguments being proposed to make EP look bad, or do most EP proponents really believe hypotheses that are obviously stronger than necessary?

Although the article makes valid points, it seem rather slanted to use these points as arguments against EP. The article has lots of spin and preoccupation with political agendas, not so much scientific objectivity.

Update (7/29/09) - For the record, I got into an extended discussion on that Newsweek article with Massimo Pigliucci (who was quoted in the article) on Facebook. It can be found here - dated June 21, 2009.

Tags: evolutionary psychology

Politics as beauty contest

Perhaps interest in politics has dropped off a lot now that the U. S. elections are over (for this year). But there's still some interesting political science that came up before the big event.

Even though political scientists, year in and year out, are as busy publishing as any other kind, quite a number of research announcements were noted recently outside of traditional professional venues. That has tapered off now, but there were a number of items that seem to call for some comment here. So I'll do some of that despite what is bound to be a declining interest in the subject.

A perennial favorite of election-oriented political research centers around questions of how the appearance of a candidate affects electoral success. That's no different this year. Here's a fairly typical example:

A Pretty Face Can Make A Difference In Whom You Vote For (10/30/08)

According to new Northwestern University research, it is not at all surprising that everyone also is talking about the great looks of vice presidential hopeful Palin.

Whether or not you believe the McCain campaign's $150,000 expenditure for Palin's wardrobe and the much-talked-about salary of her makeup artist are over the top, the decision to play up the looks of the former beauty queen is a winning strategy.

Even in 2008, a perception of competence -- a strong predictor of whether people will vote for political candidates -- is not enough to give women the winning edge in political contests, according to the new Northwestern psychology study.

For both men and women, female political candidates needed to be seen as attractive as well as competent to get their votes. ...

While gender bias related to a female candidate's attractiveness was consistent across both male and female voters, good looks was almost all that mattered in predicting men's votes for female candidates. And, true to prevailing stereotypes, competence was almost all that mattered in predicting men's votes for male candidates.

The idea that good looks positively affects electoral success has been researched many times – as well as being often suspected by a lot of people who aren't professional – in all kinds of elections from student councils on up. I discussed one study on this in a post here almost 2 years ago.

The new research I want to examine here was not entirely, or even primarily, about the importance of attractiveness in winning elections. Instead, experimental participants were first asked to rate candidates independently, based on their photos, on four different attributes: "competence", "dominance", and "approachability", as well as "attractiveness".

The politicians in question were actually candidates in 2006 U. S. Congressional elections. The politicians' photos were then presented in pairs actually competing with each other. Experiment participants were asked to chose which of each pair they would vote for if the office were actually the U. S. presidency.

The resulting data were analyzed in various ways. First, in comparison of participants' voting choice to how they had rated the candidates on each of the four attributes. Second, in comparison of candidates' gender and facial appearance to actual Congressional election outcomes. And third, in comparison between how the candidates won or lost in the simulated presidential election and in the actual Congressional election.

Since I want to focus just on the attractiveness issue, I won't attempt to summarize all the results here. You can find the summary in the research paper itself (citation below). I'll mention only two specific observations: (1) "Female candidates were more likely to win votes if they were more attractive." (2) "Male voters were significantly more likely to vote for candidates that appeared attractive." (I presume these statements represent correlations between opinions of attractiveness and voting behavior of each experimental participant.)

Now, it may be true as the research asserts, that attractiveness matters more for female candidates, while a perceptions of "competence" is relatively more important for male candidates. However, the attractiveness of male candidates (especially in contests exclusively between two males) is a still a net positive.

There's another possibility that should be considered even when voters seem to make their voting choices based on judgment of "competence" of male (or female, for that matter) candidates. Namely, that "attractiveness" (perhaps in a form not consciously associated with the term) might bias this judgment. One has to wonder exactly what visual characteristics might signify "competence" to voters, and whether certain factors – such as a "strong jawbone" (for a male) – don't contribute simultaneously to judgments of both attractiveness and competence.

Humans are fairly sophisticated in making judgments about traits like "competence", since evaluations of other people's character and ability are important in deciding whom to trust. The ability to do this reliably has a lot of evolutionary importance. This doesn't mean people are infallible about such judgments – clearly they aren't. But people probably can do better than chance in making such judgments, at least when not faced with situations where the person being judged is skilled at faking appearances. Perhaps it's more a case of detecting lack of competence, as might be signaled by poorly managed facial expressions (e. g. simply looking perplexed or "stupid").

But judgments about good looks and attractiveness are even more natural. We make them all the time, hardly giving any thought to the matter. Research has shown that people tend to make judgments about facial attractiveness very quickly. (See here.) This suggests people tend to use simple heuristics that may well be hard-wired.

Research apparently shows that even babies prefer to stare at beautiful faces. Note, too, how illustrated children's literature (and now movies) usually portrays virtuous or heroic characters as beautiful or handsome, while evil or villainous characters are ugly, often very ugly, and much to be feared. So there may be an element of social conditioning here, at least for children beyond infancy.

An interesting observation in the report of the research just mentioned, about the quickness of making judgments, is that "It seems that pretty faces 'prime' our minds to make us more likely to associate the pretty face with a positive emotion." ("Priming" is a hot topic in current psychological research.) So, comparatively speaking, a face that isn't "pretty" would be associated with less positive emotions. That alone would be enough to influence voting choices, if "everything else" is assumed to be equal.

There are different possible factors that may enter into such a judgment. So let's consider further what factors and heuristics might be used in judging facial attractiveness. It would be quite interesting to know how the various factors about to be mentioned perhaps have different effects on political choice.

A small number of factors are often suggested. One of the oldest is that the property of "youthfulness" is associated with attractiveness. That makes plenty of evolutionary sense, as fertility, reproductive capacity, and ability to nurture children all decline with age after the beginning of adulthood. It should be noted that youthfulness should be especially salient in the judgment of young people – such as the experimental subjects (college students, average age 19.5) in the research under discussion

A more recent suggestion is that "symmetry" is important, as that would tend to indicate general healthiness. (Recent research here.) That makes sense, too, but does it have any reasonably apparent relevance to voting decisions?

"Symmetry" is probably a looser criterion than in an older and fairly well-known theory of attractiveness, often called simply the "averageness" hypothesis. This holds that average phenotypes in a population are judged more attractive than phenotypes with notably atypical features. An average value on a particular facial metric (such as width of nose or chin) is considered to be what is "normal", yet for most features all to be close to average might be fairly unusual.

So "averageness" is used in a somewhat special sense here – literally, as having size and proportion of most important facial features being close to the overall average. Probably faces that have "averageness" in this sense are fairly rare, which might add to the quality of "attractiveness". So "averageness" as a descriptor of faces is not the same as "common" or "ordinary" or "typical".

Since averages of many faces will wipe out most asymmetry (e. g. some part being off center), an averaged face will be symmetrical. So facial symmetry is a more common characteristic than averageness. A symmetrical face could still have features that are far from average values in size or position.

Since facial symmetry will be more common in a population than faces that have the property of averageness (in the special sense used here), averageness is a more stringent criterion for attractivness. Consequently, a voter who perceives one candidate's face as more attractive than the candidate's opponent is making a more significant discrimination, which could have higher weight in the final choice. Indeed, two candidates might have equally symmetrical faces, or at least faces that are difficult to distinguish in terms of symmetry, yet differ considerably in averageness and hence (perhaps) in attractiveness.

And so, to the extent that people actually judge attractiveness based on averageness rather than symmetry, it will be more likely that judgment affects a voting decision. In other words, we would expect on these general considerations that attractiveness is more likely to affect voting decisions if the criterion is actually "averageness".

There is some amount of research supporting the idea that averageness is the important criterion for attractiveness, such as findings that images created by averaging photographs of many individuals tend to receive higher ratings for attractiveness. So at least for the sake of discussion, let's assume there's some validity to this notion.

Deviations from averageness do not imply deviations from symmetry, so they would not be expected to have the stronger negative implications for overall health and (hence) fertility that asymmetry does, so there would be a smaller indication of "riskiness". It would therefore be harder to understand the evolutionary importance of judging the riskiness of another person based on attractiveness if averageness is the underlying consideration. Is it possible that averageness is important in judging riskiness for other evolutionary reasons – reasons that apply to evaluating others in more general contexts than the context of mate selection?

Yes, I think so. As I wrote in my previous post, "people who are considered attractive within a population are those who are most 'typical' or 'average'. Or inversely, least atypical, least different from the largest number of people in the population. People who are considered less attractive have facial features that vary a lot from the norm, such as lips that are too thin or too thick (compared to the average), eyes too far apart or too close together, eyebrows that are too sparse or too bushy."

The evolutionary rationale at work here is that people who appear too "different" from the norm are more likely to belong to a different, more genetically distant tribe. Such people are probably less likely to deserve trust, and might even be "dangerous".

I think this matter of perceived trustworthiness vs. potential "danger" in the eyes of voters could be rather important, especially if it is unconsciously inferred from perceptions of a candidate's attractiveness. I've written more on that here, not too long ago, so I won't repeat it now.

More generally, I see conscious and unconscious issues of fear and perceived danger as especially important factors in a voter's attitudes towards, and relationship with, government. This is because, as a matter of both philosophy and sociology, one of the primary reasons for the existence of governments is to "protect" citizens from a variety of potential evils, whether they be dishonest businesspeople, common criminals, foreign and domestic terrorists, or whatever. I've written a lot more about that here.

The question, then, is whether the research now under discussion supports the idea of a connection between fear and voting behavior, or is even relevant to it. To be honest, the relevance is somewhat tentative, since it relies on the idea that there is a negative correlation between the attractiveness of a political candidate and whether a voter feels fear associated with the candidate at some level. It would be very interesting to see more research that addresses this issue more directly.

Regarding the present research itself, I have a few reservations as well. For example, the experimental participants were university students of average age 19.5 years. Quite possibly many of the participants had never even voted in a governmental election, and they certainly did not have a few decades of adult experience – with politicians, elections, and actual government performance – that could shape and inform their voting decisions. It's not surprising that individuals with little adult experience would base decisions on appearance factors.

Aside from that, there's also the question of whether the socioeconomic demographics of university students would skew the results from what would be found in the electorate as a whole. And then there's the whole other issue of possibly relevant cultural differences between the U. S. and other democratic countries.

So there's reason to suspect that typical, experienced voters, even in the U. S., might produce rather different results in a similar sort of experiment.

Here's the research paper, with some of the abstract:

The Political Gender Gap: Gender Bias in Facial Inferences that Predict Voting Behavior

Contrary to the notion that people use deliberate, rational strategies when deciding whom to vote for in major political elections, research indicates that people use shallow decision heuristics, such as impressions of competence solely from a candidate's facial appearance, when deciding whom to vote for. Because gender has previously been shown to affect a number of inferences made from the face, here we investigated the hypothesis that gender of both voter and candidate affects the kinds of facial impressions that predict voting behavior.

Joan Y. Chiao, Nicholas E. Bowman, Harleen Gill (2008). The Political Gender Gap: Gender Bias in Facial Inferences that Predict Voting Behavior PLoS ONE, 3 (10) DOI: 10.1371/journal.pone.0003666

Update on 11/24/08: I have extensively reworked the discussion about "attractiveness" and its relationship to "symmetry" and "averageness". One would like to see more experimental evidence to sort out these factors in general and specifically as to how they affect voting choice.

Tags: political science, political psychology, voting

Trading sex for resources

The title really says it all. Not much further commentary needed. Care for another example? How about bower birds?

Just Like Penguins And Other Primates, People Trade Sex For Resources

Female penguins mate with males who bring them pebbles to build egg nests. Hummingbirds mate to gain access to the most productive flowers guarded by larger males.

New research shows that even affluent college students who don't need resources will still attempt to trade sexual currency for provisions, said Daniel Kruger, research scientist at the University of Michigan School of Public Health.

The exchange of resources for sex---referred to by scientists as nuptial gifts---has occurred throughout history in many species, including humans, Kruger said. The male of the species offers protection and resources to the female and offspring in exchange for reproductive rights. For example, an arranged marriage can be considered a contract to trade resources.

However, the recent findings suggest that such behaviors are hard wired, and persist no matter how much wealth, resources or security that people obtain.

Tags: evolutionary psychology

Cheating

It's certainly appropriate – as well as hilarious – to draw the analogy between humans and slime molds. Kurt Vonnegut, Samuel Clemens, and H. L. Mencken would approve. But there's serious truth in it:

Some cheaters can keep it in their genes

A new study examining social behaviour suggests certain individuals are genetically programmed to cheat and often will do- providing they can get away with it.

The researchers looked at slime moulds - microscopic single-cell organisms or amoebae that are forced to cooperate with one another when food is in short supply. Studying slime moulds at the cellular level provides the scientists with a unique insight into the genes that may also influence human behaviour.

The international team, including biologists from The University of Manchester, found that some amoebae have the ability to use cheating tactics to give them a better chance of survival. The research - published in the journal Nature - not only demonstrates that cheating is a natural phenomenon governed by our genes but that it may be widespread among social creatures.

This is familiar territory. I wrote about it here, where the subject (among other things) was the evolutionary origins of altruism and cooperation. One needs to read that (or be familiar with the viewpoint of evolutionary psychology on the origins of morality and ethics) in order to see how the following speculations fit in.

Apparently, in many social species, there is a tendency for populations to evolve with an equilibrium mixture of cheaters and non-cheaters ("altruists"). Although cooperation increases the probability of group survival, some individuals in any group can gain an advantage by cheating, so they will tend to persist in groups as time goes on. But they can't become too numerous without harming the group's survival. So eventually some equilibrium is reached.

In the simulation of intergroup warfare I discussed in my earlier post, it was the warfare which worked against survival, so that under such conditions, there were pressures against a large equilibrium fraction of cheaters. These pressures were manifested in such things as religion and moral/ethical codes of behavior, together with formalized punishment of cheaters.

But warfare isn't the only factor that can put pressure on group survival. Simply living in a hostile or marginal environment can do it. This seems to be what happens with slime molds. Individuals can be, well, individualists until there is an existential threat.

One wonders whether this isn't what happened to the Neanderthals. Their environment was harsh. They must have migrated to that environment during favorable conditions (otherwise, why stay?), but eventually conditions got worse. If they were not able to evolve (biologically and/or socially) fast enough to reduce the percentage of cheaters, it's reasonable to suppose all would die. Modern humans living around the same time in similar environments – and who survived – perhaps were able to evolve faster. Or else they had already better capabilities for intragroup cooperation to deter cheating. Things like abilities in their brains for cheater detection, a "theory of mind", and ethical reasoning.

Other considerations suggest that worsening environmental conditions leads to more intergroup warfare (if population density is high enough, so that there is competition for resources, not merely strugle to survive, as on an island without competing groups). Such warfare would also promote cooperation and intragroup altruism over cheating.

What kind of cooperation is helpful in the non-warfare scenario? Sharing of resources (food, shelter, tools, clothing, etc.) Also communal support for raising orphaned children. Groups that had such customs and low proportions of cheaters would be more likely to survive at all.

Incidentally, one of the principal investigators (Chris Thompson) in the slime mold study, seems to know his subject pretty well. Here's another item about his slime mold research.

Tags: morality, slime molds, evolutionary psychology

Valentine's Day news

Yeah, yeah, this is late. So?

Every year we read news stories like the following right around this time. Worth thinking about. (By the way, Wagner's Prelude and Liebestod from "Tristan und Isolde" is playing on my computer right now. Synchronicity?)

And here's a little more advice you didn't ask for. First, go see the movie Juno, if you haven't yet. It's good. Really. Second, if you want to understand all this you need to get the perspective of evolutionary psychology. Matt Ridley's The Red Queen: Sex and the Evolution of Human Nature is a good place to start, if you need one.

The Differences in Gender -- Sealed With a Kiss

A kiss, it turns out, is definitely not always just a kiss.

As Valentine's Day approaches, research has begun shedding light on that most basic of all human expressions of love -- the smooch -- which has received surprisingly little scientific scrutiny.

"You'd think there would be a lot of research on kissing behavior. It's so common," said Susan M. Hughes, an assistant professor of psychology at Albright College in Pennsylvania, whose recent study is one of the first to probe snogging in depth. "But there isn't. It's really been ignored."

In fact, much about love and attraction remains mysterious.

"This is a seminal paper," said Helen Fisher, a Rutgers University anthropologist who studies love. "It's remarkable that we don't know more about these things. But love has not really been well studied until recently."

In people, kissing to express affection is almost universal. About 90 percent of human cultures do it.

Carnal Knowledge: They give pleasure; science asks why

There are some natural phenomena whose wonder only deepens upon scientific investigation.

Take the orgasm. Scientists know it involves muscle contractions. They know it makes your pupils expand, and heart rate and blood pressure surge.

But why do orgasms feel good?

I was surprised to find that this is still something of a scientific mystery - though one that a few intrepid researchers are just starting to unravel.

"Really and truly, people don't know," says Julia Heiman, director of the Kinsey Institute for Sex Research and coauthor of Becoming Orgasmic.

Right now, says Heiman, there's a big debate over how the female orgasm evolved. Researchers would also like to know just how different the female kind is from the male.

"Why is it easier for women to have multiple orgasms than it is for men?" Heiman asks. "How does it interact with attachment issues?"

There are lots of other questions, she says, but oddly, in our supposedly sex-obsessed society, it's nearly impossible to get funding for sex research.

Another complication: The orgasm question touches on some profound mysteries about how feelings and consciousness can emerge from the brain.

The Merry Band of Wrigglers

The old adage says that a wife can't change her husband, but the truth is that women for thousands of years have been shaping one crucial male attribute: sperm. Men tend to produce as many sperm as possible as quickly as possible, a manufacturing decision that sacrifices quality control: Their sperm are frequently mutated or deformed as a result. Why, then, do men make millions of sperm at once? Because they're adapting to ward off the effects of women's frequent cheating, according to a paper published in December in the Journal of Theoretical Biology.

Humans aren't especially good at monogamy. Evidence gathered from surveys and paternity tests suggests that 25 percent of women and 30 percent of men cheat on their spouses at least once during marriage. The evolutionary reason that men cheat is pretty simple: to father as many children as they can. It's more complicated for women, who can only give birth so many times. The quality of the child, then, wins over quantity. Because men with the best genes aren't always the most stable and resourceful partners (they don't have to be), women might marry the latter but cheat with the former. Then they can become pregnant with a genetically superior child who will, if her mother can pull it off, grow up with the help of her unwitting spouse.

Why Perfect Dates Make Lousy Partners

The best "catches" in dating land may be the worst choices in the long-run, new research shows.

Popular people who monitor themselves carefully in social situations and thereby appear to be the most socially appropriate are often highly sought after as romantic partners, a study finds, but these people show less satisfaction and commitment in relationships than socially-awkward people.

By self-monitoring, people assess how their actions affect others and adjust to fit the appropriateness of the situation. They screen their words and behavior to suit the people around them.

"High self-monitors are social chameleons," said Northwestern University professor of communication studies Michael E. Roloff."And, because they're quick to pick up on social cues, are socially adept and unlikely to say things upsetting to others, they are generally well-liked and sought after."

Self-monitoring is often a helpful attribute.

"Research finds [self-monitors] to be excellent negotiators and far more likely to be promoted at work than their low self-monitoring peers,” Roloff said.

But there’s a downside for high self-monitors when it comes to their romantic relationships.

"High self-monitors may appear to be the kind of people we want to have relationships with, but they themselves are less committed to and less happy in their relationships than low self-monitors," Roloff said.

More: Is Your Dating Partner Happy? With Some People It Is Hard To Know

The next item is about rats, but human folklore suggests it's very likely true for humans as well:

Females love the sweet smell of sexual success

It might be the sweet smell of success or the bitter whiff of despair, but there's something in the odour of a male rat that tells a female whether he's been copulating like crazy or starved of sex for days. And to make matters worse for frustrated males, the females much prefer the smell of road-tested studs.

The next is a fairly interesting article. Unfortunately, the link may turn into a pumpkin rather soon, since Nature isn't very generous with such things. Snarf it quickly if you want it.

Love: You have 4 minutes to choose your perfect mate

Eli Finkel and Paul Eastwick have probably seen more first dates than most. The social scientists at Northwestern University in Evanston, Illinois, have watched hundreds of videos of single people as they participate in a curious, but not unpopular, trend known as speed dating. Two participants spill their souls to each other for a set time, say four minutes, and try to decide whether they might have a future together. When the time is up, they move on to a new partner, sometimes talking to a dozen or more people in a night. ...

From a purely biological standpoint, the success of a partnership hinges mainly on one thing, reproduction. But for humans, who give birth to exceptionally weak, awkward and totally dependent babies, strong pair bonding and the sharing of parental duties can play an important part in the success of their offspring. It is strange, then, that a goal as simple as forming a pair bond could lead to an emotion as complex as romantic love. ...

Since the 1940s, social scientists have brought the tools of their trade to bear on such lofty questions. Finkel and Eastwick are now using some of the newest and most controversial techniques. The fast-paced format of speed dating could be exhilarating, daunting or perhaps even dorky for participants and observers alike. Nevertheless, the researchers say that it could help to reveal some of the mysteries behind that uniquely human emotion — love. Indeed, their research, including a paper published today1, has already started to turn up some surprises.

In the 1940s, when scientists first started to pick at the basis of human attraction, psychologists interviewed single people and asked them what they would value in a partner. Many of the values were the same in both men and women, but two things stood out in survey after survey. Women valued the wealth of their partner much more than men did, and men valued attractiveness more than women did.

These differences can even make sense in evolutionary terms. A woman looking to have children would want the support of a good provider to help her children succeed in life. Men's seemingly superficial preference for beauty was seen as a proxy for health. Symmetry, skin tone and a favourable waist-to-hip ratio could reasonably point to a woman who would not only survive childbirth, but also pass on lots of healthy genes.

More: What Men And Women Say And Do In Choosing Romantic Partners Are Two Different Matters

Other studies on such themes:

Women More Perceptive Than Men In Describing Relationships

'Love Hormone' Promotes Bonding: Could It Treat Anxiety?

Beauty Bias: Can People Love The One They Are Compatible With?

A Sense Of Scarcity: Why It Seems Like All The Good Ones Are Taken

'Hotties' Not So Hot When You're In Love, Online Dating Researchers Find

Probing Women's Response To Male Odor

Religion and war

People bitch a lot about violence featured in movies and TV, but ignore a worse problem – how the sort of real (not make-believe) violence known as war is often associated with religion.

Now there may be a better theoretical understanding of how and why this association between religion and war may exist. Two articles in the October 26, 2007 issue of Science discuss evolutionary simulations which show that war drives the joint evolution of altruism and hostility to outsiders. Based on (but going beyond) this work, we will see how religion may be associated with warfare.

The first "perspectives" article gives an overview:

The Sharp End of Altruism

Which would you prefer: a society of selfish but tolerant freetraders, or a warrior society in which people help one another but are hostile to outsiders? If you value both altruism and tolerance, neither seems ideal. Societies of tolerant altruists, however, are exceedingly rare in the simulation presented by Choi and Bowles on page 636 of this issue. Instead, altruism flourishes only in the company of outgroup hostility (parochialism), with war as both the engine of this coevolutionary process and its legacy. For a compatriot, the parochial altruist who risks his life is a shining knight, whereas the outsider encounters the sharp end of this altruism.

The second article is a technical presentation of the research itself, which was the work of Jung-Kyoo Choi and Samuel Bowles:

The Coevolution of Parochial Altruism and War

Altruism—benefiting fellow group members at a cost to oneself—and parochialism—hostility toward individuals not of one's own ethnic, racial, or other group—are common human behaviors. The intersection of the two—which we term "parochial altruism"—is puzzling from an evolutionary perspective because altruistic or parochial behavior reduces one's payoffs by comparison to what one would gain by eschewing these behaviors. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to success in these conflicts. Our game-theoretic analysis and agent-based simulations show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans, neither parochialism nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.

Unfortunately, both articles require a subscription for access.

Curiously, there appears to have been almost no reporting on this research in the usual places that report on scientific research for a general audience. (Wonder why that is....) And this is even though the Santa Fe Institute, with which one of the researchers (Bowles) is associated, did put out this press release:

The coevolution of parochial altruism and war

In "The Coevolution of Parochial Altruism and War" appearing in the October 26 issue of Science, SFI researcher Samuel Bowles and colleague Jung-Kyoo Choi of Kyungpook National University in South Korea suggest that the altruistic and warlike aspects of human nature may have a common origin.

Altruism – benefiting fellow group members at a cost to oneself – and parochialism – hostility toward individuals not of one's own ethnic, racial, or other group – are common to human nature, but we don't immediately think of them as working together hand in hand. In fact the unexpected combination of these two behaviors may have enabled the survival of each trait according to Bowles and Choi.

They show that the two behaviors – which they term "parochial altruism" – may have in fact coevolved. On the face of it joining parochialism to altruism is puzzling from an evolutionary perspective because both behaviors reduce one's payoffs by comparison to what one would gain by avoiding them. Aggression consumes resources and risks death; altruism, particularly toward those with whom we have no direct relationship, has the effect of helping other genes advance at our expense. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to the success of these conflicts.

Using game theoretic analysis and agent-based simulations Bowles and Choi show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans neither parochialsim nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.

"But even if a parochial form of altruism may be our legacy," said Bowles, "it need not be our fate." He pointed to the many examples of contemporary altruism extending beyond group boundaries, and the fact that hostility toward outsiders is often redirected or eliminated entirely in a matter of years.

Now, none of this actually mentions religion. Choi and Bowles don't discuss it. So where does religion come into it? We'll get to that shortly. But first, let's review a bit about how altruism and cooperation in human cultures are thought to have evolved.

At first, it could seem that altruism and cooperation are unlikely to have evolved in humans at all, because they seem to be traits of an individual that are of more benefit to others than to the individual who happens to possess them.

However, there is a long history of evolutionary studies that have suggested how tendencies toward altruism and cooperation could have evolved in human groups. For example, starting in 1964 William D. Hamilton argued that altruism toward blood relatives helped to favor shared genes that fostered such altruism. This was termed "kin altruism".

Additional scientific consideration of the evolution of morality, altruism, and cooperation took off in the 1970s, in the work of people like Robert Trivers and Robert Axelrod. Using game theoretic arguments and simulations they showed how another type of altruism – "reciprocal altruism" – could arise in populations where individuals interacted frequently and could learn which others had earned a reputation for dependability in their dealings with other group members.

Many, many others have written on the subject since then, such as Edward O. Wilson (e. g. Consilience, published in 1998), and Steven Pinker (How the Mind Works, published in 1997). A very good history of the subject up until 1996 can be found in Matt Ridley's The Origins of Virtue.

On the other hand, in spite of arguments advanced showing the benefits to individuals of practicing altruism within a single tribe or cultural group, the fact remains that separate, unrelated groups could easily come into conflict over access to resources (e. g. water, game, other food sources, etc.), especially in times of scarcity due to overpopulation, unfavorable climate, etc. The result would be warfare.

Many people have also studied how evolutionary tendencies have contributed to aggression and warlike behavior between competing human groups. It seems that separate groups that have relatively low genetic similarity to each other and must compete for scarce resources have a notable tendency to come into conflict with each other, and to solve their problems of overpopulation or resource scarcity by killing as many members of the other group as possible. A good exposition of such ideas can be found in this article by Keith Henson: Evolutionary Psychology, Memes and the Origin of War.

It seems very reasonable to see such considerations as the source of the very human tendency to exhibit distrust and even hostility towards other humans who are noticeably "different", especially in physical characteristics, but also when there are simply cultural differences in taste, belief systems, etc.

Furthermore, when conflict between groups does occur and takes the form of open warfare, there is a distinct advantage for groups that have a high percentage of individuals who behave altruistically and cooperatively with each other. If you accept the (somewhat controversial) notion of evolutionary "group selection", this fact provides yet another evolutionary argument for the development of a third type of altruism – parochial altruism – within groups – because groups with the higher percentage of members who cooperate with each other will tend to prevail.

However, there is another side to this story. Individuals will not entirely lose a tendency to gain personal advantage through selfish behavior (such as hoarding food). Altruism can be disadvantageous for an individual if it goes too far, so there is some evolutionary pressure against it also. In an environment where scarcity of resources is not a large problem, individuals can serve their own interests by being open to interaction with members of other groups – especially for commerce and trading of "excess" goods. Individuals who are selfishly willing to trade their goods with members of other groups for the best exchange they can achieve will tend to do better for themselves since they are willing to "sell" to the highest bidder, regardless of group membership.

This, then, is the setting on which Choi and Bowles based their simulation. They considered two kinds of traits an individual could have. One related to altruism (A) vs. selfishness (N, for "not altruistic"). The other related to tolerance (T) vs. hostility (P, for "parochial") towards member of other groups. Any given individual could have one of four possible combinations (AT, AP, NT, NP). They started with groups having members with differing proportions of each possible combination.

Absent intergroup conflict, NT individuals (the most tolerant but selfish) tend to be most successful, and AP the least successful. But when intergroup conflicts occur, groups with the most AP types do better than groups with the most NT types. The simulations proceeded over thousands of generations, and a variety of parameters, all believed to be consistent with what is known about late Pleistocene hunter-gatherer human tribes, were tested.

The net result was that groups with many NT or AP individuals can both be successful, depending on how much warfare occurs (which depends on environmental conditions). But in most cases, groups with high proportions of NP or AT individuals lose out under any conditions. So one conclusion is that in order to have a lot of altruism within a group, you have to expect a lot of parochial intergroup hostility. Conversely, in order to have groups with a lot of tolerance towards other groups, you should expect less altruism and cooperation within the group. Choi and Bowles maintain that the same results tend to arise from a wide variety of different initial conditions.

True, this is "only" a simulation study. And it rests on the assumption that altruism and parochialism (or their opposites) are heritable traits (which alternatively might be transmitted culturally rather than genetically). But it seems to give results that accord well with what we know of human history. And that's where religion enters the picture. (Choi and Bowles do not discuss religion, so what follows is based on their findings, but also the contributions of others.)

In evolutionary terms, why is it that religion is so widespread in human societies? There are a variety of plausible explanations. One is that religion provides the rationale for moral and ethical principles that promote intergroup cooperation and altruism. The argument made by supporters of this idea – such as David Sloan Wilson in his book Darwin's Cathedral: Evolution, Religion, and the Nature of Society – is that societies and cultures with strong religion-based ethical and moral principles have a competitive advantage over other groups.

However, what the Choi-Bowles simulation suggests is that this advantage is realized only when groups often engage in conflict and war. For otherwise, there is an advantage for groups with lots of tolerance towards other groups, and lots of free-traders working for their own self-interest.

So, ironically, religion may have developed as a result of intergroup warfare, as a social artifact that helps justify intragroup altruism that actually was selected for because of the warfare. And at the same time, religion would also incorporate a justification for the intergroup hostility and aggression that arose from the same evolutionary process.

In other words, evolutionary pressures tend to bring about an association of religion and warfare. Note that this is not saying religion "causes" war. Indeed, evolutionary theory suggests that overpopulation and resource limits usually tend to be what "causes" war. But when such conditions prevail, it isn't too surprising to find a close association between religion and war. Just recall the slogan some religious believers are so fond of: "There are no atheists in foxholes." (In other words, most of the cannon fodder found in foxholes and military cemeteries is (or was) religious believers.)

Of course, most religions aren't pro-war full time. Many religious believers oppose war because of their faith. Nevertheless, most religions have their holy warriors, such as Mujahideen and Crusaders. (Military equipment of predominantly Christian nations is sometimes named a Crusader.) Most religions have their own versions of Onward Christian Soldiers. And most religions celebrate war in other ways.

But is there scientific evidence of a relation between religion and war? Yes. Consider this:

When God Sanctions Violence, Believers Act More Aggressively

Reading violent scriptures increases aggressive behavior, especially among believers, a new study finds. The study by University of Michigan social psychologist Brad Bushman and colleagues helps to illuminate one of the ways that violence and behavior are linked.

"To justify their actions, violent people often claim that God has sanctioned their behavior," said Bushman, faculty associate at the U-M Institute for Social Research and lead author of the article published in the March 2007 issue of Psychological Science. "Christian extremists, Jewish reactionaries and Islamic fundamentalists all can cite scriptures that seem to encourage or at least support aggression against unbelievers."

To be sure, this is hardly a new observation. Mark Twain, as well as many others before him, had already nailed it.

Update (11/13/07): I see that I missed one of the U. S. military's pricey toys proposed artillery systems (which was canceled in 2002) that used the "Crusader" moniker – the Crusader 155mm Self-Propelled Howiter. See here or here. Onward, Christian soldiers, indeed.

Are Women Being Scared Away From Math, Science, And Engineering Fields?

Are Women Being Scared Away From Math, Science, And Engineering Fields?

Have you ever felt outnumbered? Like there are just not that many people like you around? We’ve all felt outnumbered in one situation or another and walking into a situation in which you sense the possibility of being ostracized or isolated can be quite threatening.

One group that may experience this kind of threat is women who participate in math, science, and engineering (MSE) settings- settings in which the gender ratio is approximately 3 men to every 1 woman

I don't see how there could be much doubt that this is a problem.

However, the explanation may not be entirely that ostracism or isolation alone is threatening. Evolutionary psychology could provide another part of the explanation, because it seems likely that for most of the time humans have been evolving, it actually has been more dangerous for women to participate in groups where men far outnumber them. Sensitivity to sexual harassment is rather likely to be in the genes.

One has to wonder whether men would show the same degree of signs of discomfort in an experiment where groups in which women predominated were shown to the experimental subjects. It's not clear whether this was addressed in the research.

Similar considerations of evolutionary psychology could be a part of the explanation for this finding:

Female Anxiety: Females More Likely To Believe Negative Past Events Predict Future

A new study finds that young girls and women are more likely to believe that negative past events predict future events, compared to boys and men. And that, according to researchers, may help explain why females have more frequent and intense worries, perceive more risk, have greater intolerance for uncertainty, and experience higher rates of anxiety than males.

Why opposites attract romantically

Just in time for Valentine's day:

New Study Is First To Link Romantic Relationships To Genes

New research suggests that choosing a mate may be partially determined by your genes. A study published in Psychological Science has found a link between a set of genes involved with immune function and partner selection in humans.

Vertebrate species and humans are inclined to prefer mates who have dissimilar MHC (major histocompatibility complex) genotypes, rather than similar ones. This preference may help avoid inbreeding between partners, as well as strengthen the immune systems of their offspring through exposure to a wider variety of pathogens.

The study investigated whether MHC similarity among romantically involved couples predicted aspects of their sexual relationship. “As the proportion of the couple’s shared genotypes increased, womens' sexual responsivity to their partners decreased, their number of extra-pair sexual partners increased and their attraction to men other than their primary partners increased, particularly during the fertile phase of their cycles,” says Christine Garver-Apgar, author of the study.

On the other hand... While this may apply to non-human mammals like mice and chimps, there could be trouble in our species with parters who are too opposite. If she prefers classical music, luxury cruising, a neat and tidy house, and eventually wants a large family, while he prefers hip hop, mountain climbing, a relaxed attitude towards domestic order, and doesn't care that much for kids, there could be trouble brewing.

Even if they have great sex together.

Why blue-eyed men prefer blue-eyed women - but not vice versa

Most people learn in high school (if they're paying attention) that human eye color is a genetic trait which follows fairly simple rules. The primary gene that controls eye color exists in several forms, called alleles. The protein produced by one of the alleles causes the eyes to be brown, while a variant allele producing a slightly different protein does not. Since the human genome contains two copies of each gene, if even one of these copies is the allele for brown eyes, brown will be the resulting color, regardless of the other allele. Such an allele is said to be "dominant". Another eye color (e. g. blue) will result only if both copies of the gene are non-brown alleles. Such alleles are said to be "recessive".

Children receive one copy of each paired chromosome from each parent. It follows that if one parent has two copies of a dominant gene, every one of their children will receive at least one copy, regardless of what the other parent has. All children of this mother and father will have brown eyes, if even one parent has two brown eye alleles, and even if the other parent has two blue eye alleles.

If both parents have one brown and one blue allele, then for any particular child, there's a 1 in 4 chance of receiving two brown alleles, a 1 in 4 chance of receiving two blue alleles (the only case that will result in blue eyes), and a 2 in 4 chance of receiving one brown and one blue allele (hence brown eyes). If one parent has blue eyes, and the other has both a brown and a blue allele, then the odds are 50/50 for each of their children to have either brown or blue eyes. So if one or both parents have brown eyes, it's possible for them to have blue-eyed children. But when both parents have blue eyes, so all of their alleles are for blue eyes, all of their children will have blue eyes. In that case, if any child has brown eyes, it must be the case that one parent – most likely the male – is not the biological parent. Oops.

So a blue-eyed man has an interesting advantage over men with brown eyes – a very dependable way of knowing that he is not the father of a particular child, provided he mates with a blue-eyed woman. Further, a blue-eyed man who regards blue-eyed women as more attractive than women of other eye colors is more likely to mate with blue-eyed women. And so such a blue-eyed man has a selective advantage over other blue-eyed men who have no such preference (or a preference for brown-eyed women).

This would be advantageous, at least in prehistoric times, if in addition such a man was less inclined to provide for a child without blue eyes – even if there was no conscious recognition that the child could not be his own. Some recent research has indicated that blue-eyed men sometimes actually, if unconsciously, do have a tendency to regard blue-eyed women as more "attractive", and hence (presumably) are more likely to choose them as mates:

Blue Eyes -- A Clue To Paternity

Eighty-eight male and female students were asked to rate facial attractiveness of models on a computer. The pictures were close-ups of young adult faces, unfamiliar to the participants. The eye color of each model was manipulated, so that for each model's face two versions were shown, one with the natural eye color (blue/brown) and another with the other color (brown/blue). The participants' own eye color was noted.

Both blue-eyed and brown-eyed women showed no difference in their preferences for male models of either eye color. Similarly, brown-eyed men showed no preference for either blue-eyed or brown-eyed female models. However, blue-eyed men rated blue-eyed female models as more attractive than brown-eyed models.

Since a mother almost always can be sure a given child is hers (except for rare events like accidental switching of infants), a mechanism that provides a way to recognize that a child isn't her own provides little additional advantage. And so, blue-eyed women do not have an evolutionary advantage from a tendency to regard blue-eyed men as more attractive than others. So they do not, in fact, have that tendency.

If you're looking around for an example of specific, and unexpected, behavior for which evolutionary psychology offers the simplest explanation, this may be a good choice.

Update 8/3/08: There is more recent news on this subject here and here.

Tags: biology, evolutionary theory, evolutionary psychology, eye color, blue eyes

The Literary Animal

Fair warning: the following is a review of a review of a book I haven't yet read... though it sounds mighty interesting. I'm just using the review as an excuse to sound off on some ideas which occurred to me in reading the review -- ideas that seem important, though there's no hint that either the reviewer of the book or any of the authors of essays in the book seem to have considered them.

The book in question is The Literary Animal: Evolution and the Nature of Narrative (Rethinking Theory), edited by Jonathan Gottshall and David Sloan Wilson (also here). (It's not scheduled to be released until November, so I have a reasonable excuse for not having read it. Perhaps the publishers will send me a review copy...) The book appears to be heavily academic in nature and consists of 12 essays by luminaries in such fields as literature, literary criticism, anthropology, biology, and evolutionary psychology.

The review is by David Michelson, a graduate student in English literature and evolutionary studies at Binghamton University. (One would presume that Michelson has been mentored, at least informally, by David S. Wilson, a professor of biology and anthropology at Binghamton.) The review itself appears at eSkeptic.

A little context to begin with. In the past few decades university departments of literature, literary studies, "critical theory", and the like have generally fallen under the hegemony (a term often used by denizens of these departments) of scholars of a "postmodernist" persuasion. This is rather a controversial point of view (at least among those who don't hold it). Michelson, for instance, alludes to it as "the rather insular culture of anti-scientism and radical political posturing that is commonplace in most English and cultural studies departments today." Adherents of postmodernism often hold a very jaundiced view, to put it mildly, of science in general and evolutionary theory in particular. They regard most science (to use Michelson's words) as "myopically and detrimentally western, white, and patriarchal in practice."

However, I don't care to go into that debate now. (See books like Higher Superstition for more background.) I only mention it to set the context, which is that there are now many scholars and scientists who want to challenge the postmodernists on their own turf, by applying evolutionary theory to the study of literature itself. Many of the contributors to The Literary Animal are apparently in this camp. This is flagrant lèse-majesté.

But what does it mean to apply evolutionary theory to the study of literature? What might such a thing as "evolutionary literary studies" actually consist of? I can't fairly answer that, since the idea comes as a bit of a surprise to me, and I haven't read the book under review. Perhaps this, from Michelson, gives us some idea:

The Literary Animal tackles a huge topic: the nature and representation of narrative and its role in the evolutionary scheme of human affairs, past and present. Despite other essay collections on evolution, literature and the arts, The Literary Animal is the first volume of evolutionarily focused essays on the multifaceted nature of narrative, which is defined here as oral and written literature. This definition encompasses theater, film, television, novels, poetry, erotica, folktales, the narrative activities of journal writing and the hypothesized narrative processes underlying our conscious thought.

I wonder if it's fair to say that a major part of this undertaking could be described as the application of evolutionary psychology to literary studies. That might be a little too narrow, but let's run with it anyway. At this point, I have a feeling of déjà vu. There have been previous attempts to apply some form of "science" to literary studies. A few decades ago, before the rise of postmodernism, when Freudian psychology and other forms of psychoanalysis were still in vogue (and not yet discredited scientifically), there was a lot of writing about "psychoanalysis and literature". (Indeed, many postmodernists still come from a psychoanalytic background. How is that even "modern", let alone "postmodern"?)

Are we simply dealing here with the application of a rather newer (yet still controversial) brand of psychology to literary studies? Whatever the answer to that may be, it may at least help to illuminate the nature of the task here. That is, there are two important kinds of questions that any flavor of psychological theory ought to try to answer about literature.

First: What does the psychological theory tell us about how and why the people who create "literature" go about their work? What motivates their labor? What psychological processes occur in their minds in the act of composing a story?

Second: Does the psychological theory help us understand the motives, thoughts, and behaviors of the fictional characters that occur in literature? Has the author used this theory explicitly in drawing the characters, or do the characters simply serve as credible examples of the theory's predictions? How compatible, and illuminating, are the theory and the literary story at telling us something about "human nature" through the behavior of characters in the story?

And this brings up the really important question: what is "literature" anyway? Answers to this question are presumably to be found among the essays in The Literary Animal as Michelson describes it:

The editors believe their collection speaks to three major themes, each addressing a specific question:

• What is literature about?
  
• What is literature for?
  
• What does it mean for a seemingly nonscientific subject such as literature to be approached from the perspective of a scientific discipline such as evolution?

At this point, I find myself wanting to know the answers as they would be given by yet another flavor of psychology: neuropsychology. It's not that I have any bone to pick with evolutionary psychology. I like the theory a lot, and find it very illuminating in explaining many things about human behavior. However, ultimately, anything that is the product of biological evolution winds up being incorporated in the material structure of an organism. So what might the facts of our neurobiology be able to tell us about some of the questions mentioned above?

I don't know how to answer that, but I think I do know where to start looking. One thing we know (or think we know) is that the frontal cortex of the brain is the place where most of the planned, deliberate behavior of humans seems to be generated. Unlike most other animals (as far as we can tell), humans think, deliberate, plan, and scheme a great deal before undertaking a course of action that has some conscious goal in view (presuming they have sufficient time, of course). It may be that humans are not so unique within the animal kingdom as they think they are, but that's not important. What matters is that neuroscience seems to know at least a little about how this sort of planning occurs in the frontal cortex.

Frontal lobes have been found to play a part in impulse control, judgement, language, memory, motor function, problem solving, sexual behavior, socialization and spontaneity. Frontal lobes assist in planning, coordinating, controlling and executing behaviour. People who have damaged frontal lobes may experience problems with these aspects of cognitive function, being at times impulsive; impaired in their ability to plan and execute complex sequences of actions; perhaps persisting with one course of action or pattern of behaviour when a change would be appropriate (perseveration).

It seems to me that the creating of literature is an example of this kind of planning in action. Whenever we are faced with an important decision, certain kinds of thoughts go through our minds. For example, consider a decision about taking a new job. We think about the kinds of people we will be working with and dealing with on the job. We think about how we will fit into that situation, about what sort of challenges we will face, and how or whether we might be able to respond. We think about the kinds of things that can go right or go wrong if we take the job. We think about our exit strategy if things do go wrong. But these are precisely the sort of things that an author thinks about in plotting a story! And the frontal cortex is where this kind of thinking takes place. Whatever mechanisms exist in the brain to do this kind of analysis, they are at the service of an author who is creating literature. Presumably it matters little whether one is applying this kind of analysis to one's own life or to the lives of fictional characters.

And all this is just as true for the consumers of literature as well as for the creators of it. Practically everyone with a functioning frontal cortex should be able to enjoy exercising that part of the brain as applied to a set of hypothetical characters in hypothetical situations as they do to theirselves, other people they know, and real-life situations. It's the same process whether it's "real life", a TV soap opera, or a Shakespearean tragedy. There is pleasure in exercising our physical selves, whether it's our leg muscles (in running or biking) or our frontal cortex. In the latter case, there are various older name for the activity: pretending, "make believe", or vicarious experience. In theater, one calls such a thing a "play", for very good reasons.

I can be even more specific. I think that the frontal cortex implements "models" of the real world. That is, we have complex theories about the things and actors that are found in the real world, and about how those constituents of the real world interact causally with each other. When the actors are other humans, we even have theories about how their minds work (Dennett's intentional stance). We are continuously running such models, just as models programmed on a computer are run to predict the evolution of everything from hurricanes to the expansion of the universe. Presumably there is a lot that neurobiology can, or will eventually be able to, say about how such models are implemented in the frontal cortex.

That, in turn, should tell us an enormous amount about how literature is created and enjoyed.

Every story is a kind of thought experiment. What will happen if we take some set of characters, place them in a certain environment, and present them with various challenges? Running such thought experiments (when one has time off from dealing with problems in the real world) is a form of play that almost all humans enjoy. It's a form of play that few, if any, other animals can enjoy. And it's obviously a useful adaptation that evolution has provided us with. But it's much more useful to know exactly how this works in the brain than simply to know we have this ability.

Why is the ability to create and run such models of the real world such a useful adaptation? Probably that's obvious, but one can be more specific. I think that an individual's success, in whatever complex task the individual is trying to accomplish, is directly related to how accurately the individual's model reflects the "real world". Is it a good model, or a false one? And success is further related to how well the brain can run this model against a range of varied inputs.

The model, for a primitive human, might deal with the behavior of a particular type of prey animal that the individual is tasked to hunt. For a modern human, the model might deal with a certain occupation, like running a restaurant. In the latter case, there are a variety of important submodels dealing with behavior of potential customers, behavior of employees, handling financial transactions with suppliers, the preparation of food that the expected customers will enjoy, and so on. How accurate those models are as a whole will determine the prospective restauranteur's success or failure. (The latter is much more common.)

The model itself is not provided by evolution. Evolution gives only the ability to run the model in one's brain. The model itself is a form of software provided by an individual's culure. A primitive hunter learns to hunt by being taught, preferably by the most able hunter of the older generation. (Though a few basic skills, like strong and accurate throwing ability, can be provided by evolution.) A modern prospective restauranteur learns the craft from a good culinary academy and (hopefully) from apprenticeship to a talented mentor.

And what is one of the largest collections of off-the-shelf models that a culture can provide? Literature. The intelligent prospective military officer reads Homer or Sun Tzu. The prospective politician reads Machiavelli or Sandburg's Lincoln. The prospective scientist reads Watson's Double Helix. The prospective master of the art of living reads Shakespeare or Lao Tzu. (There may be as much "fact" as "fiction" in some of these examples, but "fiction" can be just as useful, as long as it's true to the "real world".)

Any decent theory of literature should tell us something about how the best examples of such literary models are constructed and how to most effectively run such models in our frontal cortices. Perhaps even about how we might implement such models ourselves.