Tuesday, September 15, 2009

The right-handed ape   posted by Razib @ 9/15/2009 06:20:00 PM

Via Anthropology.net, The prehistory of handedness: Archaeological data and comparative ethology:
Homo sapiens sapiens displays a species wide lateralised hand preference, with 85% of individuals in all populations being right-handed for most manual actions. In contrast, no other great ape species shows such strong and consistent population level biases, indicating that extremes of both direction and strength of manual laterality (i.e., species-wide right-handedness) may have emerged after divergence from the last common ancestor. To reconstruct the hand use patterns of early hominins, laterality is assessed in prehistoric artefacts. Group right side biases are well established from the Neanderthals onward, while patchy evidence from older fossils and artefacts indicates a preponderance of right-handed individuals. Individual hand preferences and group level biases can occur in chimpanzees and other apes for skilled tool use and food processing. Comparing these findings with human ethological data on spontaneous hand use reveals that the great ape clade (including humans) probably has a common effect at the individual level, such that a person can vary from ambidextrous to completely lateralised depending on the action. However, there is currently no theoretical model to explain this result. The degree of task complexity and bimanual complementarity have been proposed as factors affecting lateralisation strength. When primatology meets palaeoanthropology, the evidence suggests species-level right-handedness may have emerged through the social transmission of increasingly complex, bimanually differentiated, tool using activities.

The evolutionary background of handedness is of interest because there are correlates with left-handedness when it comes to individual differences. Handedness can also be somewhat confusing. For example, I am right-handed when it comes to writing (of less relevance today when I generally type). But I am strongly left-handed in basketball, switch-hit in baseball (slower bat speed left), and can throw a football with either arm comfortably (greater strength left, but better touch right, and I tend to side-arm with the left).

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Monday, March 23, 2009

Brain gene expression differences as a function of time   posted by Razib @ 3/23/2009 05:52:00 PM

Transcriptional neoteny in the human brain:
In development, timing is of the utmost importance, and the timing of developmental processes often changes as organisms evolve. In human evolution, developmental retardation, or neoteny, has been proposed as a possible mechanism that contributed to the rise of many human-specific features, including an increase in brain size and the emergence of human-specific cognitive traits. We analyzed mRNA expression in the prefrontal cortex of humans, chimpanzees, and rhesus macaques to determine whether human-specific neotenic changes are present at the gene expression level. We show that the brain transcriptome is dramatically remodeled during postnatal development and that developmental changes in the human brain are indeed delayed relative to other primates. This delay is not uniform across the human transcriptome but affects a specific subset of genes that play a potential role in neural development.

Here are the 4 classes of gene expression trajectories they're focusing on:

They found that there was a relative enrichment of genes which exhibited human neoteny, with delayed expression:


We analyzed the genes affected by the neotenic shift in the human prefrontal cortex with respect to their histological location, function, regulation, and expression timing. First, with respect to their histological location, we used published gene expression data from human gray and white matter...and found that, in both brain regions, human neotenic genes are significantly overrepresented among genes expressed specifically in gray matter...but not among genes expressed in white matter....

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Sunday, October 26, 2008

Some people better language learners?   posted by Razib @ 10/26/2008 05:23:00 PM

Well, I assume most people probably accept that some people are better than average at learning languages, while others are not as good. But the reasons for this aren't quite clear. PNAS has a paper out on this topic, Brain potentials to native phoneme discrimination reveal the origin of individual differences in learning the sounds of a second language. I find the ScienceDaily summary comprehensible, and one of the researchers says:
"Therefore, these results show that there is a positive correlation between specific speech discrimination abilities and the ability to learn a second language, which means that the individual ability to distinguish the specific phonemes of the language, both in the case of the mother tongue and in the case of other languages, is, without a doubt, a decisive factor in the learning process, and the ability to speak and master other languages," concludes Begona Diaz.


Tuesday, June 17, 2008

Sheep herders are not sheep???   posted by Razib @ 6/17/2008 10:44:00 AM

Ecocultural basis of cognition: Farmers and fishermen are more holistic than herders:
It has been proposed that social interdependence fosters holistic cognition, that is, a tendency to attend to the broad perceptual and cognitive field, rather than to a focal object and its properties, and a tendency to reason in terms of relationships and similarities, rather than rules and categories. This hypothesis has been supported mostly by demonstrations showing that East Asians, who are relatively interdependent, reason and perceive in a more holistic fashion than do Westerners. We examined holistic cognitive tendencies in attention, categorization, and reasoning in three types of communities that belong to the same national, geographic, ethnic, and linguistic regions and yet vary in their degree of social interdependence: farming, fishing, and herding communities in Turkey's eastern Black Sea region. As predicted, members of farming and fishing communities, which emphasize harmonious social interdependence, exhibited greater holistic tendencies than members of herding communities, which emphasize individual decision making and foster social independence. Our findings have implications for how ecocultural factors may have lasting consequences on important aspects of cognition.

I reviewed the Richard Nisbet's Geography of Thought 5 years ago. There seems to be a substantial literature on this topic in regards to different dominant modes of cognition. There is a great deal of overlap, and these tendencies seem to be highly plastic (e.g., you can "train" someone to think in an alien mode rather quickly), but on the margins the average differences between societies have likely mattered a great deal. Would anyone, for example, claim that the individualism of the Celts vis-a-vis the Romans in their fighting styles served them well? In contrast, total nomads (as opposed to farmers who practice a great deal of animal husbandry) can arguably leverage individual action against slow moving group formations to a far greater extent (e.g., as evidenced by the shift by the Romans themselves from fixed infantry based defenses toward mobile armies during the late Empire). And of course both When Histories Collide and Farewell to Alms seem to be making the case that particular economic and social systems have fostered customs and traits which are beneficial to the flourishing of capitalism.

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Sunday, March 30, 2008

Religion: biology ↔ psychology ↔ sociology ↔ history   posted by Razib @ 3/30/2008 01:18:00 AM

On the most recent bloggingheads.tv you can watch Paul Bloom explaining why he thinks the propensity for theism is an innate bias of our species. Several years back Bloom wrote a piece for The Atlantic, Is God an Accident?, where he makes a similar case. But the general outline of Bloom's line of thinking is actually most powerfully argued in Scott Atran's In God's We Trust. The cognitive psychologists and anthropologists who work within this paradigm operate under some background assumptions in regards to our mental architecture. First, human cognitive states are strongly biased by innate tendencies which have a biological origin. Perception and language acquisition are easily explained by nativist treatments, but Atran and others have argued that more obscure biases such as folk biology also exist, while other domains such as theory of mind are broadly accepted within the scholarly community.

One can conceive of a model where on a lower structural level a set of biological parameters interact with exogenous inputs to generate a set of psychological biases. But the subsequent mental skills are not independent, and I suspect broadly distributed ones contingent upon environmental inputs such as language are among the least encapsulated from other cognitive domains. It seems rather clear that language aptitude is one of the components which can be used to explain the facility for mathematical abstraction, but it can not explain the totality of this skill. Cognitive anthropologists have also noted that preliterate peoples have extreme difficulties with comprehending the logic or rationale behind syllogistic reasoning (see Kluge: The Haphazard Construction of the Human Mind), suggesting that there are strong cultural preconditions to particular styles of thinking which may seem natural to us. Even though language, reading and writing all are learned, they are also facilities which we as humans have an innate aptitude for because of our neurobiology (language is obviously "more innate" insofar as it seems that our priming is so strong that it might emerge out of any conventional socialization processes, which literacy is historically and culturally contingent).

Another working assumption of Bloom, Atran & co. is that a great deal of our cognition is implicit. Again, this is well accepted among the community of scholars. It stands to reason that our conscious mind lives under the illusion that it is all that there is, but a substantial body of work tells us that most of our conscious decisions are strongly influenced and primed by subconscious background parameters. Not only does this include priming an individual immediately prior to a psychological task, but it also includes the enormous swath of territory which falls under the category of intuitive thinking. A dense network of background connections and implicit inferences is often an outsized shadow of the visible chains of reflective rationality. Even in structurally transparent and deductive disciplines such as mathematics the dark-net of subconscious facts and assumptions loom large in the process of creativity.

The fact that psychological biases have many different upstream neurobiological and environmental parameters, as well as the syngergistic nature of cognition which produces subsequent cognitive abilities (e.g., mathematics or painting which includes perspective), means that a hypothesis that posits a God Module is obviously going to be false. There are god modules such as the medulla oblongata, but only insofar as they are necessary for the proper functioning of a human in general. But it seems highly unlikely that there is one localized region of the brain which is specifically the causal element for belief in God (i.e., if said region is damaged atheism ensues, but most other cognitive function is left unscathed). This assumption doesn't derive simply from an a priori understanding of how the mind works; we can see it in how the phenotype of theism plays out. The pathological character of many aphasia sufferers is pretty obvious; in contrast the avowed attitude toward the God hypothesis is characterized by a rich range of opinion in terms of both plausibility and character. In other words, religion is more properly characterized as a quantitative trait which exhibits a wide range of continuous variation, subject to a norm of reaction.

Do note that I said avowed attitude; when it comes to theism there are many ways to evaluate belief or lack thereof. Despite wide variations in verbal descriptions of the particular flavor of deity believers assent to, psychologists know that the implicit model of most humans in regards to supernatural agents is strongly constrained. This is one of the main reasons that many cognitive scientists believe that our mental architecture is rigged toward a belief in god; not only do the gods which individuals from widely disparate societies model in their mind's eye differ from the entities which they avow a conscious belief in, but those psychological constructs exhibit a very strong universal central tendency. In other words, the human model of a god, or supernatural agent if you will, seems to be predicated on the various elements of universal neurobiology. Unless strongly constrained by experimental or observational methodologies as in natural science, or a rigorous formalism as in mathematics, our species tends to reason extremely sloppily so that inferences unmoored from experience or unchanneled by formalism invariably explore an enormous sample space of possibilities starting from the same axioms. That humans tend to conceive of the same god-construct despite lack of communication or outside input suggests that the channeling is occurring on an innate level.

Additionally, not only do theists no matter their affiliation agree upon an intuitive model of God, but so do atheists. Paul Bloom has noted that the offspring of secular parents are usually innate Creationists. Many of the ideas bracketed within "religion" are very natural and intuitive. In our gut we know them to be "true" without deep reflection or analysis. Atheism can not exist without theism because it is simply a negation of the latter. It is a conceit of many atheists that children are naturally unbelievers and that they are indoctrinated into a religious system of belief. This is correct; children are indoctrinated into a system of belief, but more specifically they are indoctrinated into a system, not a belief. That in almost all human societies a supernatural model of the world is numerically dominant strongly suggests that these sorts of belief do not necessarily need the institutional scaffolding of established churches or professional priesthoods. Rather, it seems that these features of religion are secondary and subsequent, and that they operate upon the preexistent assumptions of the population. Some atheists live under the delusion that the withering of organized religion will result in the collapse of belief in God or the supernatural; this is not so. Though the extremely high rates of theism in some societies may be an upper bound contingent upon social and historical conditions, in no society does it seem there exists an inverse dynamic where theism is extant at trivial levels. Note that even after 70 years of state sanctioned atheism Russians have now swung back to a default affiliation with their historical religious identity as Orthodox Christians. This is not to say that Russians are a religiously fervent people; rather, the high levels of atheism espoused during the Soviet era was a function of a skewing of the environmental inputs which shifted the median value of the trait distribution. With the norm relaxed the distribution has shifted back.

The plausibility of theism doesn't need to be something we note only in terms of macrosocial metrics in regards to religious affiliation cross-culturally. As I imply above, theism is at root a psychological phenomena, and the bundle of biases and presuppositions which our biology confers upon us stack the deck in terms of weighting the plausibility of god concepts. This applies to atheists as well. We might not believe in god on the conscious level, but that does not mean that we are immune to the priming affect of agents, and likely supernatural agents as well. The folk wisdom about there being no atheists in foxholes is a reflection of this assumption. Now I'm not going to tell anyone who says they don't believe in god that deep down they really do believe in god; rather, I simply believe that many of the psychological characteristics which prime one for finding god plausible are present in those who consciously assert that they don't believe in gods. For example many atheists may feel unnerved in cemeteries despite a materialist world-view; the psychological response may be a result of social conditioning, but it is also possibly a cognitive reflex at an intersection of environmental inputs (think snake aversion as something similar).

So far I have alluded to biology & psychology, but what about the higher-level social sciences? Paul Bloom and most cognitive scientists are focused on the first two disciplines, so they tend to strongly adhere to a model that religion is a byproduct of our cognitive architecture. An analogy might be the heat given off by the functioning of a car's engine; the heat is not a designed product of the various components of the engine, but it is an inevitable byproduct of the physical processes entailed by combustion. Similarly, theism may not be an adaptation to any exogenous selection pressure, but the intersection of various adaptive psychological characters such as agency detection, theory of mind and folk biology necessarily lead to the plausibility of supernatural agents within the minds of most humans. Because of Bloom's disciplinary focus he tends to not be very open toward a functionalist explanation for theism; that theism (or religion) is an adaptive trait which increases individual fitness. Insofar as explanations at a lower level of organization are preferable to those at a higher level, I think that Bloom's skepticism is warranted. But even cognitive anthropologists who tend to focus on the psychological dimensions of theism can't dismiss the social aspects of religion, and a substantial body of social science research implies that variation in religious belief might track other social variables.

Instead of repeating the functionalist explanations elucidated by scientists such as David Sloan Wilson (see Darwin's Cathedral), I think it is easy to illustrate the relation of these various theories by using an analogy with narrative. Despite the attempts of authors who dabble in "experimental fiction" it seems pretty obvious that a great story has a dimension of temporal permanence derived from the timelessness of the primary themes and styles. The Epic of Gilgamesh speaks to us even after 4,000 years, and many of its motifs are still extant in the heroic fantasy genre. Despite the lack of qualitative originality in plot and the constraints upon the plausible range of the psychology of characters we continue to consume fiction because our brains are attracted to particular themes arranged in a familiar structure. One could contend that fiction is a waste of time, but it seems likely that the same mental ticks which draw us to compelling stories are useful in other areas of life.

But narrative is not only a byproduct of our promiscuous mental functioning, it is an essential part of myth-making and religion. The cognitive anthropologist Pascal Boyer has reported on research which suggests that minimally counterintuitive stories are the ones which are most memorable and "sticky" over the long-term. In other words, experimental fiction is just too weird to really make a deep impact, you don't have any common basis for associative memory to operate. In contrast, exceedingly conventional and banal narratives just don't add anything new to the base of data. A boring story is a boring story. But a familiar scenario with just the right amount of spice adds enough twists and turns within the comprehensible base to make it memorable enough to catalog and retrieve later. This explains why most science fiction and fantasy tends to constrain the deviation from normality; you can't relate to a story where most of it is unfamiliar or disorienting.

Of course narrative is an essential part of religion. Even "primitive" religions have a robust narrative base; tales of gods & heroes unfettered by abstruse theologies. The story of Jesus as depicted in the Gospels has a power to draw people in and inspire them toward belief & action. In contrast, despite the fact that Christians accept the divine provenance of Deuteronomy, very few believers have ever recounted to me how it inspires them or serves as the ground of their faith. Just as narrative emerges naturally as a byproduct of our overall psychological architecture, it also immediately slots into the overall cultural entity which we label "religion." I suspect the exact same model is applicable to gods; their plausibility precedes their integration into a religious framework and does not derive from direct adaptation. But the universal nature of religious frameworks as well as storytelling implies that these byproduct traits are almost always subject to co-option by cultural systems which are canalized toward a particular configuration.

But what is driving that canalization? I suspect there is some functional selection going on. Like many social science generalizations I'm not sure I can be very general here. David Sloan Wilson has collected data which shows that religious fundamentalism is more noticeable in economically depressed regions. Which way does the causality run here? I suspect that it is generally in the direction of economic insecurity to religious fundamentalism. The sociologist of religion Rodney Stark has elucidated a rational choice inspired framework which posits that religious institutions are firms which offer products which satisfy a fragmented market of religious consumers. This model seems highly plausible for the United States, but there are doubts as to its validity in other cultures where religious switching is not as socially acceptable or viable. Similarly, many of Wilson's adaptive arguments for the functional significance of religion are quite likely more relevant in societies which lack the accoutrements of the welfare state so that religious institutions have few competitors or substitutes. In other words, generalizations about the functional significance of religious institutions may not hold across many environments. Nevertheless, though generalizations on higher levels of organization are less impressive when compared to the relatively simplicity and universality of a biopsychological paradigm, I think it is necessary that we analyze the expression of religion outside the bounds of the human mind. After all, though religious ideas are fundamentally mental, they are embedded within a social matrix and have a geopolitical relevance in terms of how they shape human relations and action.

We can, for instance, see that over the past few thousand years local tribal religions have ceded ground to the dominance of institutional religions which often have multiple products under the same brand name. The number of supernatural agents seems to be decreasing through a process of competition concurrent with the decrease in polities, languages and ethnic groups. But though institutional religions have gone through a process of consolidation this dynamic has limits; the fragmentation of Christianity during the Reformation or the schisms within the first centuries of Islam attest to this. Though religious institutions far exceed the scale of Dunbar's Number, a One-World-Religion seems as plausible as a One-World-Government. Psychologists have also attempted to move into broader domains of social science. Scott Atran has been at the forefront of attempting to synthesize the cognitivist viewpoint with an analysis of the nature of religious terrorism. Atran emphasizes the power of religious narratives & rituals in cementing group cohesion. The functionalist interpretation on this is pretty obvious; this is a case where heat from one process is quickly being utilized to generate energy through another.

To some extent analysis of religious is like the species problem; we should measure the definition against the utility it provides in a particular context. Species define the joints around which nature is carved, and religion is a label for a cluster of integrated characters which we humans imbue with ontological significance. Both species and religion are important to understand, and can serve as frameworks for robust research programs, but a final definition will never be attained so long as scholars in disparate fields have distinct ends. A diversity of ends does not imply that these ends are contradictory, rather, when you have a many dimensional character it is necessary to observe from a variety of angles to obtain the clearest picture.

Addendum: I want to add something: theism & religion are very robust phenomena. This is why adaptationist explanations are so compelling. That's why an analogy to misunderstandings due to intuitive physics (e.g., flat earth, variance of acceleration in proportion to mass of an objection) is informative, but only to some extent. Overactive agency detection feeds into something which is far more than the sum of their parts, the falsifiable manifestations of religion such as Young Earth Creationism can resist disconfirmation because of their association with psychological tendencies such as group conformity enforced by common rituals & beliefs. To say religion is a spandrel or exaptation understates its interaction with other aspects of human culture so as to make it inevitable and resistant to suppression.

Related: The nature of religion and Breaking the Spell, Modes of religion, Who Dan Dennett think he be foolin'?, An evolutionary anthropology of religion, , God lives, deal with it!, , Belief & belief in belief, Logical consistency is irreligious, God & moralityAre people naturally religious? Yes.... , The round-eyed Buddha, Nerds are nuts, Atheism, Heresy and Hesychasm, The God Delusion - Amongst the unbelievers , Innate atheism & variation across societies, "Hard-wired" for God, Buddhism, a religion or not?, Why do people believe in God?, Is religion an adaptation?, Theological incorrectness - when people behave how they shouldn't....sort of , The gods of the cognitive scientists

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Saturday, October 27, 2007

No sympathy for statistics   posted by Razib @ 10/27/2007 02:37:00 PM

Sympathy and callousness: The impact of deliberative thought on donations to identifiable and statistical victims. I think the figure to the left really says it all. People give more money to individuals who are identifiable as opposed to plain clear statistics, but adding statistics to a face actually suppresses giving! One of the reasons that I think people dislike data and statistics is that they're rather stupid and can't remember the context or process them analytically. But these data do suggest I think that another reason is that numbers are emotionally deadening and probably don't give result in the reward sense that one wants or needs. Putting an identifiable person into a statistical framework removes the emotional impulse as well. This is all rather disheartening when you think about the nature of representative democracy.


Friday, September 07, 2007

What women want   posted by p-ter @ 9/07/2007 09:50:00 PM

Published today in PNAS is a paper by Peter Todd and colleagues on mate choice in humans. Of course, everybody and their mother has already commented on it, based on a press release, or a Fox News article, or something (science bloggers: disdainful of science press coverage in their own field, yet unthinkingly accepting of it in others?). It's always interesting, though, when some paper of possibly general interest comes out, to compare the reactions of people familiar with the line of research with those not. In this case, compare the reactions of Kate at The Anterior Commisure or the Mungers at Cognitive Daily, two blogs which touch on cognitive science and psychology, with the reactions of Sheril at The Intersection (a marine biologist) or Rob Knop at Galactic Interactions (a physicist). The former seem to recognize that they can't say much without reading the study, and use it as a jumping-off point to talk about the psychology of attraction in general, while the latter seem to have no trouble immediately identifying a fatal flaw in the researchers' assumptions. Hm. Something to think about (or don't think about it. If any scientist were to publicly criticize my research methods based on a Fox News article, I'm going to go out on a limb and say I'd be pretty damn pissed).

Anyways, now that the study is out, it turns out everybody was focusing on an entirely peripheral point in the paper. Yes, women are more "choosy" than men, and yes, money and status matter to women, and yes, looks matter to men, but that's not news. As Jason Malloy points out, if that's all this paper were to show, it wouldn't be in PNAS. I'm going to quote him in full (unless he objects):
This dataset looks laughably amateur when there are other recently analyzed speed-dating (and related) datasets with literally 1000s of people. Here is a speed-dating study from last year (PDF):

"We have data on approximately 1800 women and 1800 men who participated to 84 speed dating events (or markets) organised between January 2004 and October 2005"

This paper found women were definitely more choosy:

"Striking gender differentials in proposal behaviour are observed in the data. As emerged in many previous psychological studies [Trivers 1972], women are much choosier than men. On average, women choose 2.6 men and see 45 percent of their proposals matched, while men propose to 5 women and their proposals are matched in only 20 percent of the cases. About 36 percent of men and 11 percent of women do not get any proposal..."

And here's an even larger (and IMO more interesting) study from last year focusing on preferences through an online dating network (PDF):

"Our analysis is based on a data set that contains detailed information on the attributes and online activities of approximately 22,000 users in two major U.S. cities."

Again, females more choosy:

"Note that men appear much more receptive to first-contact e-mails than women. The median man (in terms of photo attractiveness) can expect to hear back from the median woman with an approximately 35% chance, whereas the median woman can expect to get a reply with a more than 60% chance. Figure 4.2 also provides evidence that more attractive men and women are "pickier.""

Also, more status domains were important to women than men, such as income and occupation:

"Our revealed preference estimates corroborate several salient findings of the stated preference literature. For example, while physical attractiveness is important to both genders, women... place about twice as much weight on income than men."

While men could compensate for ugliness with more money, women couldn't compensate for less attractiveness at all.

Finally, yet another speed dating sample from last year with a sample size of 400 found the same things among college students (PDF):

"Women put greater weight on the intelligence [As measured by SAT score] and the race of partner, while men respond more to physical attractiveness."
So this study isn't breaking any new ground in that regard (which seems to be the one people have focused on). Rather, the part that seemed novel to me (though I think I may have heard of research like this before) was to ask people beforehand what they're looking for in a partner, then compare that to their actual behavior. It's actually kind of amusing:
Table 3 depicts the correlations (separated by sex) between choice scores and stated preferences. The correlations for women are generally low for all domains except physical appearance and overall preferences (i.e., "ideal mate value" compared with "selected mate value"). Notably, men show a consistently negative relationship between stated preferences and chosen attributes. These counterintuitive correlations are significant for physical appearance and healthiness and marginally significant for overall preferences. Conversely, the results revealed a positive (although not significant) correlation between men's stated attractiveness preferences and the mean observer-rated attractiveness of their chosen women. As a whole, these findings indicate that there is a rather poor match between our sample's verbally stated preferences for mate traits and the preferences they expressed through their actual mate choices
That is, people essentially lie to themselves (or perhaps only to observers) about what they're looking for in a partner. Some commenters have fixated on the role of culture in preferences as something not accounted for by this study, but the data seem to suggest that, while it's not culturally acceptable to say that you're judging someone by their looks, well, that's what ends up happening anyways.

Note to commenters: please do not tell me how you met your wife/girlfriend and how your personal experience differs with the conclusions here, or about your successes/failures in online dating. I don't care.


Saturday, August 25, 2007

Drink as I say   posted by Razib @ 8/25/2007 01:07:00 PM

I'm reading When Baghdad Ruled the Muslim World: The Rise And Fall of Islam's Greatest Dynasty, a history of the Abbasids. This on page 169 caught my attention:
...the caliph called for wine. A golden goblet was brought and the drink was poured into it. Ma'mum drank and handed it to Hasan....Hasan, a good Muslim had never drunk wine, yet to refuse could be seen as an insult to the caliph...'Commander of the Faithful,' he said, 'I will drink it with your permission and following your order,' for if the caliph himself had commanded him to do it, how could it conflict with Islam? The caliph replied that if it had not been his order, he would not have held out the goblet to him. So the tension was relaxed and they drank together

There are many references in this book to the consumption of wine at the court of the Abbasids, and even the patronage of a genre of poetry focused upon wine. I knew the general outline of this, and amongst Muslim rulers alcohol consumption doesn't seem that rare. I recall that the Mughal ruler Jehangir was an alcoholic, as was Saud bin Abdul Aziz, the king of Saudi Arabia in the 1950s and early 1960s (his problems with alcohol were one of the reasons that he was forced to abdicate by his brothers). Of course, Islam prohibits the consumption of alcohol, and yet here you have the titular spiritual leaders of the Islamic world, the caliphs, making it a normal part of their lifestyle. What's going on here?

One of the main reasons that I have generally turned a skeptical eye toward explanations of religious constraint upon behavior are these sorts of examples. From an atheist perspective I had always tended to view religions as clear and distinct sets of axioms; but operationally the practice seems far more subject to social consensus and individual rationalization. This isn't only an issue with religions, I have known of environmentalists who drive SUVs, self-proclaimed social conservatives who are heavy users of drugs and indulge in non-standard sexual practices, and so on. I'm sure most people can repeat such examples. Years ago when I found out that George H.W. Bush had switched from being pro-choice to pro-life, as had Ronald Reagan to some extent (Reagan's pro-choice period was more that he simply signed laws decriminalizing abortion in California as governor), I assumed this was conscious political opportunism. The same for Al Gore or Jesse Jackson, who made the inverted transition. And surely some aspect of political calculation was at work here on the ultimate level, but what about the proximate cognitive processes? Humans are good at rationalization, and I'm not sure anymore that the elder Bush or Reagan were insincere in their rather fortuitous conversions. Or, at least part of their minds were pretty convinced that their change in opinion had more to do with reflective shifts in the underlying assumptions and values and not an exogenous push due to circumstance.

In short, humans beings perceive themselves to be reflective beings shaped by essential axioms open to conscious inspection. But the reality is that human behavior and psychology seems to exhibit a great deal of contextual contingency which shape a host of cognitive processes insulated from conscious inspection. We regularly seem to make up, and believe in, stories which reinforce our self-perception that we are rational beings with free will who make decisions and form beliefs by carefully taking into account data filtered via our avowed norms. But cognitive psychology shows that humans can be easily influenced by priming inputs which they are not conscious of in regards to the choices they make, all the while happily regaling researchers with their theories that sketch out the underlying causal factors behind their behavior. Yet it seems here that as in the case above the reason is posterior to the act; constructed post facto to give intellectual support to decisions made via other means.

Surely there is a method to the madness, and the outline of human behavior is constrained by a host of concrete parameters (biology, sociology, history, even rational calculation!). But, the biases which serve as weighted parameters in the function that generates the distribution of human behavior are likely more complex, contingent and opaque to the naked eye then we might have hoped for. Just as "friction," "bounded rationality" and "behavioral economics" are emerging as necessary and essential tools in economics, so broad brush histories and anthropologies must take into account the multi-dimensional nature of human psychology and the disjunction between the stories we tell and the dynamics which drive us.

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Saturday, July 07, 2007

Quick links   posted by p-ter @ 7/07/2007 01:43:00 PM

Robin Hanson at Overcoming Bias has a couple interesting posts up-- the first on a paper suggesting that conspicuous consumption in men and conspicuous "nice-ness" (my term) in women are "costly signals" in the sense of the handicap principle, and the second on a sociobiological theory for the demographic transition.

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Monday, June 25, 2007

Writing and how we think   posted by Razib @ 6/25/2007 09:51:00 AM

There have long been scholars who try to show that writing systems have been important players in world history (e.g., the Chinese system vs. the alphabetic ones). Chris of Mixing Memory reports some interesting data which suggests that these sort of conjectures need not just be hypotheses, at least on the first order level of effect:
However, recent evidence argues against this explanation. Several studies have shown that adults who learned to write in a right-to-left writing system (as in Hebrew), as opposed to left-to-right (as in English), tend to put agents on the right and patients on the left, with actions tending to be represented as moving from right to left. In other words, the inherent spatial aspect of action representations could be a product of the writing system we use, rather than the wiring of our brain....

...The fact that the children who couldn't write didn't show the bias, while adults educated in left-to-right and right-to-left writing systems showed opposite, language-consistent biases in agent placement strongly suggests that it is the writing system, and not the innate wiring of the brain, that our action representations are inherently spatial.


Friday, June 01, 2007

Tonal languages, ASPM, and MCPH   posted by p-ter @ 6/01/2007 06:26:00 PM

The article Razib mentioned earlier on the correlation between genetics and language type has been published. Effectively, the results of the paper are in their one figure (right), which shows population frequency of the two alleles on the x and y axes. The filled squares represent non-tonal languages, and the empty squares tonal languages. There's an association between allele frequencies and language type, and the magnitude of the association is an oulier when considering other loci in the genome, suggesting that it is not simply due to population migration and history. My comments:

1. I have never seen an article so apologetic about its conclusions. About every other sentence explains what they have not shown-- a gene for "speaking Chinese", a proof of causality of the alleles, any sort of racial anything. Probably the result of unsympathetic reviewers.

2. The approach they take is one that's likely to be widely employed as more world-wide genotype data become available-- make a hypothesis that there should be a correlation between allele x and world-wide variable y, then test the correlation for a number of loci. If your allele x is an outlier, you've found something interesting. I'm not sure of the best way to analyse this data, nor am I sure the outlier approach is really effective. Some sort of statistical framework would be nice here, as a way of truly assessing the significance of a result like this.

3. As both ASPM and MCPH are polymorphic within populations, the best way to test the authors' hypothesis (as I'm sure they're well aware) is to do an association study on any of the variables they mention as being involved in slight biases towards a given language type. This would be interesting. But the authors also claim that the lingistic bias towards a language type is small, but amplified by cultural transmission, so possibly undetectable on an individual level. So can this hypothesis be falsified?

4. I'm trying to figure out the logic behind the placement of the dotted lines in the figure. It's not halfway between to min and max allele frequencies. It's not computed in any manner. Yet they make claims about the relative frequencies of each type of language in each quadrant. This seems highly questionable-- the human mind is highly capable of detecting patterns and forming groups, even when data are random. I'm not claiming the data points here are random, simply that the positioning of the lines in the figure serves to bias our thinking (note that a slight move to the right of the vertical line, or a move up to 50% on the horizontal line, would put a population in a quadrant they don't think it should belong in).

Overall, the paper is suggestive. Maybe highly suggestive? But I'd wait for a bit more data before coming to any conclusions.

UPDATE: Mark Lieberman at Language Log posts on the study, explaining more concretely the difficulties of the outlier approach. Bob Ladd, one of the authors of the study, then responds in a guest post:
Consequently, we've gone about as far as we can go with statistics; the only real confirmation that we are onto something will now come from experimental work demonstrating the existence of the hypothesized genetically-induced "cognitive bias" in individuals, followed by studies clarifying the neurological basis of the bias. As Daniel Nettle says in his Commentary on the print version of our paper (appearing soon), our work is really hypothesis-generating rather than hypothesis-testing.
We are now generating precise hypotheses about the nature of the bias, and hope to start testing them soon.
Now, it's certainly true, as Mark says, that our geographical correlations would mean more if they had proceeded from some experimental demonstration of some sort of genetically linked, language-related, cognitive/behavioral/perceptual difference. But given the widespread assumption (rooted in the Boasian tradition, but with a significant contemporary boost from Chomsky) that the human language faculty is absolutely uniform across the species, it's very unlikely that we would have been able to get funding to look for such a difference first. So we started by doing something we could do on our own without such support, namely testing the apparent correlation. Having done that, we hope we are now in a better position to apply for funding for the expensive part of the research

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Saturday, May 26, 2007

Cognitive biases and science - II   posted by Razib @ 5/26/2007 03:04:00 PM

The Science article, Childhood Origins of Adult Resistance to Science, has now been re-packaged for Edge. I have read Paul Bloom's work before so none of this is surprising, though I would offer that he has the cognitive psychologist's bias, so to speak, of not addressing the impact of the variation of human intelligence on the ability of people to comprehend scientific concepts. Even if you can't reproduce all the findings of a given science, high IQ people often have a large database of facts they can cross-reference, a toolkit of rough & ready heuristics and raw analytic power through which concepts can be filtered. The less intelligent often can't make recourse to these cognitive faculties, so the power of authorities looms large and there must be an extra sensitive focus on their credibility. Interestingly, I've found that google actually makes stupid people even more efficiently stupid, they simply proceed to use the search engine to collect an enormous assemblage of moronic sources to reinforce their beliefs. Of course, there's the reality that smart people are often quite stupid outside of their knowledge domain, though eminence within their own field often results in self-deception as to the source of their beliefs outside of their area of expertise (i.e., they attribute their positions to reasoned analysis when in many cases they are simply expressing the beliefs of their social set).


Monday, May 21, 2007

Cognitive biases and science   posted by p-ter @ 5/21/2007 09:52:00 AM

It may be obvious that people tend to trust their intuition over data, but some counterintuitive facts or forces are questioned (i.e. evolution), while other are not (i.e. electricity, the non-flatness of the earth). This review (entitled Childhood Origins of Adult Resistance to Science-- I can't tell if the title is deliberately clever or entirely serious) takes a look at why, concluding (perhaps unsurprisingly) that resistance to scientific information is exacerbated in societies "where nonscientific ideologies have the advantages of being both grounded in common sense and transmitted by trustworthy sources." I tried to pick out some select quotes, but instead I'm just putting the whole thing below the fold. It's a fascinating article, and very well-written:
Scientists, educators, and policy-makers have long been concerned about American adults' resistance to certain scientific ideas (1). In a 2005 Pew Trust poll, 42% of respondents said that they believed that humans and other animals have existed in their present form since the beginning of time, a view that denies the very existence of evolution (2). Even among the minority who claim to accept natural selection, most misunderstand it, seeing evolution as a mysterious process causing animals to have offspring that are better adapted to their environments (3). This is not the only domain where people reject science: Many believe in the efficacy of unproven medical interventions; the mystical nature of out-of-body experiences; the existence of supernatural entities such as ghosts and fairies; and the legitimacy of astrology, ESP, and divination (4). This resistance to science has important social implications, because a scientifically ignorant public is unprepared to evaluate policies about global warming, vaccination, genetically modified organisms, stem cell research, and cloning (1).

Here we review evidence from developmental psychology suggesting that some resistance to scientific ideas is a human universal. This resistance stems from two general facts about children, one having to do with what they know and the other having to do with how they learn.

The main source of resistance concerns what children know before their exposure to science. Recent psychological research makes it clear that babies are not "blank slates"; even 1-year-olds possess a rich understanding of both the physical world (a "naïve physics") and the social world (a "naïve psychology") (5). Babies know that objects are solid, persist over time (even when out of sight), fall to the ground if unsupported, and do not move unless acted upon (6). They also understand that people move autonomously in response to social and physical events, act and react in accord with their goals, and respond with appropriate emotions to different situations (5, 7, 8).

These intuitions give children a head start when it comes to understanding and learning about objects and people. However, they also sometimes clash with scientific discoveries about the nature of the world, making certain scientific facts difficult to learn. The problem with teaching science to children is thus "not what the student lacks, but what the student has, namely alternative conceptual frameworks for understanding the phenomena covered by the theories we are trying to teach" (9).

Children's belief that unsupported objects fall downward, for instance, makes it difficult for them to see the world as a sphere—if it were a sphere, the people and things on the other side should fall off. It is not until about 8 or 9 years of age that children demonstrate a coherent understanding of a spherical Earth (10), and younger children often distort the scientific understanding in systematic ways. Some deny that people can live all over Earth's surface (10), and when asked to draw Earth (11) or model it with clay (12), some children depict it as a sphere with a flattened top or as a hollow sphere that people live inside.

In some cases, there is such resistance to science education that it never entirely sticks, and foundational biases persist into adulthood. One study tested college undergraduates' intuitions about basic physical motions, such as the path that a ball will take when released from a curved tube (13). Many of the undergraduates retained a common-sense Aristotelian theory of object motion; they predicted that the ball would continue to move in a curved motion, choosing B over A in Fig. 1. An interesting addendum is that although education does not shake this bias, real-world experience can suffice. In another study, undergraduates were asked about the path that water would take out of a curved hose. This corresponded to an event that the participants had seen, and few believed that the water would take a curved path (14).

The examples so far concern people's common-sense understanding of the physical world, but their intuitive psychology also contributes to their resistance to science. One important bias is that children naturally see the world in terms of design and purpose. For instance, 4-year-olds insist that everything has a purpose, including lions ("to go in the zoo") and clouds ("for raining"), a propensity called "promiscuous teleology" (15). Additionally, when asked about the origin of animals and people, children spontaneously tend to provide and prefer creationist explanations (16). Just as children's intuitions about the physical world make it difficult for them to accept that Earth is a sphere, their psychological intuitions about agency and design make it difficult for them to accept the processes of evolution.

Another consequence of people's common-sense psychology is dualism, the belief that the mind is fundamentally different from the brain (5). This belief comes naturally to children. Preschool children will claim that the brain is responsible for some aspects of mental life, typically those involving deliberative mental work, such as solving math problems. But preschoolers will also claim that the brain is not involved in a host of other activities, such as pretending to be a kangaroo, loving one's brother, or brushing one's teeth (5, 17). Similarly, when told about a brain transplant from a boy to a pig, they believed that you would get a very smart pig, but one with pig beliefs and pig desires (18). For young children, then, much of mental life is not linked to the brain.

The strong intuitive pull of dualism makes it difficult for people to accept what Francis Crick called "the astonishing hypothesis" (19): Dualism is mistaken—mental life emerges from physical processes. People resist the astonishing hypothesis in ways that can have considerable social implications. For one thing, debates about the moral status of embryos, fetuses, stem cells, and nonhuman animals are sometimes framed in terms of whether or not these entities possess immaterial souls (20, 21). What's more, certain proposals about the role of evidence from functional magnetic resonance imaging in criminal trials assume a strong form of dualism (22). It has been argued, for instance, that if one could show that a person's brain is involved in an act, then the person himself or herself is not responsible, an excuse dubbed "my brain made me do it" (23). These assumptions about moral status and personal responsibility reflect a profound resistance to findings from psychology and neuroscience.

The main reason why people resist certain scientific findings, then, is that many of these findings are unnatural and unintuitive. But this does not explain cultural differences in resistance to science. There are substantial differences, for example, in how quickly children from different countries come to learn that Earth is a sphere (10). There is also variation across countries in the extent of adult resistance to science, including the finding that Americans are more resistant to evolutionary theory than are citizens of most other countries (24).

Part of the explanation for such cultural differences lies in how children and adults process different types of information. Some culture-specific information is not associated with any particular source; it is "common knowledge." As such, learning of this type of information generally bypasses critical analysis. A prototypical example is that of word meanings. Everyone uses the word "dog" to refer to dogs, so children easily learn that this is what they are called (25). Other examples include belief in germs and electricity. Their existence is generally assumed in day-to-day conversation and is not marked as uncertain; nobody says that they "believe in electricity." Hence, even children and adults with little scientific background believe that these invisible entities really exist (26).

Other information, however, is explicitly asserted, not tacitly assumed. Such asserted information is associated with certain sources. A child might note that science teachers make surprising claims about the origin of human beings, for instance, whereas their parents do not. Furthermore, the tentative status of this information is sometimes explicitly marked; people will assert that they "believe in evolution."

When faced with this kind of asserted information, one can occasionally evaluate its truth directly. But in some domains, including much of science, direct evaluation is difficult or impossible. Few of us are qualified to assess claims about the merits of string theory, the role of mercury in the etiology of autism, or the existence of repressed memories. So rather than evaluating the asserted claim itself, we instead evaluate the claim's source. If the source is deemed trustworthy, people will believe the claim, often without really understanding it. Consider, for example, that many Americans who claim to believe in natural selection are unable to accurately describe how natural selection works (3). This suggests that their belief is not necessarily rooted in an appreciation of the evidence and arguments. Rather, this scientifically credulous subpopulation accepts this information because they trust the people who say it is true.

Science is not special here; the same process of deference holds for certain religious, moral, and political beliefs as well. In an illustrative recent study, participants were asked their opinion about a social welfare policy that was described as being endorsed by either Democrats or Republicans. Although the participants sincerely believed that their responses were based on the objective merits of the policy, the major determinant of what they thought of the policy was, in fact, whether or not their favored political party was said to endorse it (27). Additionally, many of the specific moral intuitions held by members of a society appear to be the consequence, not of personal moral contemplation, but of deference to the views of the community (28).

Adults thus rely on the trustworthiness of the source when deciding which asserted claims to believe. Do children do the same? Recent studies suggest that they do; children, like adults, have at least some capacity to assess the trustworthiness of their information sources. Four- and five-year-olds, for instance, know that adults know things that other children do not (like the meaning of the word "hypochondriac") (29), and when given conflicting information from a child and from an adult, they prefer to learn from the adult (30). They know that adults have different areas of expertise: Doctors know how to fix broken arms, and mechanics know how to fix flat tires (31, 32). They prefer to learn from a knowledgeable speaker than from an ignorant one (29, 33), and they prefer a confident source to a tentative one (34). Finally, when 5-year-olds hear about a competition whose outcome was unclear, they are more likely to believe a person who claimed that he had lost the race (a statement that goes against his self-interest) than a person who claimed that he had won the race (a statement that goes with his self-interest). In a limited sense, then, they are capable of cynicism (35).

These developmental data suggest that resistance to science will arise in children when scientific claims clash with early emerging, intuitive expectations. This resistance will persist through adulthood if the scientific claims are contested within a society, and it will be especially strong if there is a nonscientific alternative that is rooted in common sense and championed by people who are thought of as reliable and trustworthy. This is the current situation in the United States, with regard to the central tenets of neuroscience and evolutionary biology. These concepts clash with intuitive beliefs about the immaterial nature of the soul and the purposeful design of humans and other animals, and (in the United States) these beliefs are particularly likely to be endorsed and transmitted by trusted religious and political authorities (24). Hence, these fields are among the domains where Americans' resistance to science is the strongest.

References and Notes

* 1. H. Nowotny, Science 308, 1117 (2005).[Abstract/Free Full Text]
* 2. "Teaching of Creationism is Endorsed in New Survey" New York Times, 31 August 2005, p. A9.
* 3. A. Shtulman, Cognit. Psychol. 52, 170 (2006). [CrossRef] [ISI] [Medline]
* 4. M. Shermer, Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time (Owl Books, New York, 2002).
* 5. P. Bloom, Descartes' Baby (Basic Books, New York, 2004).
* 6. E. Spelke, Cognition 50, 431 (1994). [CrossRef] [ISI] [Medline]
* 7. G. Gergely, Z. Nadasdy, G. Csibra, S. Biro, Cognition 56, 165 (1995). [CrossRef] [ISI] [Medline]
* 8. V. Kuhlmeier, K. Wynn, P. Bloom, Psychol. Sci. 14, 402 (2003). [CrossRef] [ISI] [Medline]
* 9. S. Carey, J. Appl. Dev. Psychol. 21, 13 (2000). [CrossRef] [ISI]
* 10. M. Siegal, G. Butterworth, P. A. Newcombe, Dev. Sci. 7, 308 (2004). [CrossRef] [ISI] [Medline]
* 11. S. Vosniadou, W. F. Brewer, Cognit. Psychol. 24, 535 (1992). [CrossRef] [ISI]
* 12. S. Vosniadou, in Mapping the Mind, L. Hirschfeld, S. Gelman, Eds. (Cambridge Univ. Press, New York, 2003), pp. 412–430.
* 13. M. McCloskey, A. Caramazza, B. Green, Science 210, 1139 (1980).[Abstract/Free Full Text]
* 14. M. K. Kaiser, J. Jonides, J. Alexander, Mem. Cogn. 14, 308 (1986). [ISI] [Medline]
* 15. D. Kelemen, Cognition 70, 241 (1999). [CrossRef] [ISI] [Medline]
* 16. M. Evans, Cognit. Psychol. 42, 217 (2001). [CrossRef] [ISI] [Medline]
* 17. A. S. Lillard, Child Dev. 67, 1717 (1996). [CrossRef] [ISI] [Medline]
* 18. C. N. Johnson, Child Dev. 61, 962 (1990). [CrossRef] [ISI] [Medline]
* 19. F. Crick, The Astonishing Hypothesis (Simon & Schuster, New York, 1995).
* 20. This belief in souls also holds for some expert ethicists. For instance, in their 2003 report Being Human: Readings from the President's Council on Bioethics, the President's Council described people as follows: "We have both corporeal and noncorporeal aspects. We are embodied spirits and inspirited bodies (or, if you will, embodied minds and minded bodies)" (21).
* 21. The President's Council on Bioethics, Being Human: Readings from the President's Council on Bioethics (The President's Council on Bioethics, Washington, DC, 2003).
* 22. J. D. Greene, J. D. Cohen, Philos. Trans. R. Soc. London Ser. B 359, 1775 (2004). [CrossRef] [ISI] [Medline]
* 23. M. Gazzaniga, The Ethical Brain (Dana, Chicago, 2005).
* 24. J. D. Miller, E. C. Scott, S. Okamoto, Science 313, 765 (2006).[Abstract/Free Full Text]
* 25. P. Bloom, How Children Learn the Meanings of Words (MIT Press, Cambridge, MA, 2000).
* 26. P. L. Harris, E. S. Pasquini, S. Duke, J. J. Asscher, F. Pons, Dev. Sci. 9, 76 (2006). [CrossRef] [ISI] [Medline]
* 27. G. L. Cohen, J. Pers. Soc. Psychol. 85, 808 (2003). [CrossRef] [ISI] [Medline]
* 28. J. Haidt, Psychol. Rev. 108, 814 (2001). [CrossRef] [ISI] [Medline]
* 29. M. Taylor, B. S. Cartwright, T. Bowden, Child Dev. 62, 1334 (1991). [CrossRef] [ISI] [Medline]
* 30. V. K. Jaswal, L. A. Neely, Psychol. Sci. 17, 757 (2006). [CrossRef] [ISI] [Medline]
* 31. D. J. Lutz, F. C. Keil, Child Dev. 73, 1073 (2002). [CrossRef] [ISI] [Medline]
* 32. J. H. Danovitch, F. C. Keil, Child Dev. 75, 918 (2004). [CrossRef] [ISI] [Medline]
* 33. M. A. Koenig, F. Clement, P. L. Harris, Psychol. Sci. 15, 694 (2004). [CrossRef] [ISI] [Medline]
* 34. M. A. Sabbagh, D. A. Baldwin, Child Dev. 72, 1054 (2001). [CrossRef] [ISI] [Medline]
* 35. C. M. Mills, F. C. Keil, Psychol. Sci. 16, 385 (2005). [CrossRef] [ISI] [Medline]
* 36. We thank P. Harris and F. Keil for helpful comments on an earlier version of this manuscript. Neither author received any funding for the preparation of this article.


Sunday, April 08, 2007

Why people believe in weird things....   posted by Razib @ 4/08/2007 12:01:00 AM

1 in 5 Americans believe in reincarnation, the same numbers as in Europe. One can ascribe this to the influence of Indian religion, but recall that reincarnation has ancient roots within Europe. My own suspicion is that reincarnation is an "evoked" belief which many humans find plausible. Like the existence of gods it doesn't have to be "invented" by a genius, cognates naturally emerge in a parallel manner across human societies due to the universal mix of psychology & environment. I have made no secret of the fact that my own position is that modal human theism likely emerges from conventional and prosaic human cognitive processes (e.g., agency detection), but what about supernatural ideas like reincarnation? A new paper, The false fame illusion in people with memories about a previous life (popular press summary), sheds some light on the modal cognitive processes which might account for belief in past lives which seem to be a recurring phenomenon in human culture. Researchers found that those who claimed to have past life memories made consistent and systematic errors in a particular psychological task. In short, it seems that these individuals tended to be more suggestible and prone to allowing mistakes in associational memory creep into their recollections. It seems possible then that cognitive "misfiring" opens up an avenue whereby these strange mental concepts can easily slip into the domain of plausibility (innate mind-body duality already seems to convince us about the permanence of the soul). The control group was less likely to make these mistakes, and were also less likely to believe in reincarnation, but this does not negate the general relationship and the likelihood that similar (if attenuated) cognitive processes are at work on a broad scale across human societies.


Tuesday, February 20, 2007

Religion & Politics & Derb   posted by Razib @ 2/20/2007 11:35:00 PM

Check out Derb's latest column for NRO.

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