I am not sure that so many scholars have argued that \"religious belief is solely guided by representational content\", but if they have, well, their position seems obviously wrong to me...

Who would deny that the kind of religious beliefs you have access to, is the most important factor in determining which religious beliefs you end up adopting? In a world where Judeo-christian beliefs are widespread, people are more likely to adopt them, not necessarily because they are conformist, but because you choose from the pool of existing beliefs.

It seems just as obvious to me that this dynamic would make some religions spread much more than others, even in the absence of cognitive factors, through a series of historical accidents.

The same applies to flu epidemics: some are very sucessful, some are not. Some varieties of flu are more contagious than others, but this does not explain the huge differences in success between different epidemics. Chance does.

So, yes, of course, Zeus is much less popular than Jesus. And, no, fictional religions are not successful if you measure success by the standards of today\'s big religions. And I can see no obvious link between the cognitive properties of Zeus beliefs and their current lack of success.

I thought Gervais and Henrich were attacking a straw man when they made their point, but maybe I was wrong.

Even though I agree with Olive Morin that the standard cognitive explanation does not exclude other factors (its an all else being equal-argument), Gervais & Henrich do point to a important problem often alluded to, when you present cognitive theories to scholars of religion. One question, often appearing, is why certain ideas successfully spread in new areas, whereas others fail miserably. I agree that reputations systems involved in tracking the source of reliable information necessarily must be part of the answer, but here I would like to point to another way of understanding this problem. A problem in the standard account seems to me to be the, relatively unfounded, conceptual atomism involved. The epidemiological spread of gods such as Zeus, Jesus, Ganesh is explained as a result of the internal content, i.e. the cognitive optimum, totally independent of their relation to other concepts. I believe this is flawed for a number of reasons. First of all, concepts are not remembered independently but in relation to other concept that gives them a locally embedded, pragmatic meaning. Thus, ’Jesus’ has an altogether different meaning when uttered as a curse than when said by a priest during mass. Further, the evocation of one concept will potentiate the evocation of other concepts as a simple priming effect. ’Jesus’ will give rise to a number of predictions as to the following relevant concepts, and thus automatically relate a concept to other concepts.

So the argument would be that concepts form relatively stable clusters, and that the adoption of a concept depends on the relative strength of related concepts forming such pragmatically relevant models. Let me give an example: Lord Krishna has been proselytized intensively in Western Europe by ISKCON (also known as Hare Krishna) for almost 40 years but with a very low rate of success. In contrast, the equally Indian concept of reincarnation has become hugely popular despite ardent opposition from majority churches. Why? Besides the reputation systems obviously at work tracking the source of new ideas, the two concepts relates very differently to other prevalent conceptual structures in the Western world. Whereas reincarnation got hook up with positive concepts of progress, evolution and individualism when introduced in the Western world by theosophist in the late 19th Century, Krishna has no such conceptual underpinning, and adopting Krishna as your god with full commitment will force you to give up on a long series of other concepts and introduce wholly different ones instead. This is not only cognitively burdensome, but it will also automatically segregate you from other individual not sharing your new conceptual structure. Thus in the first case we find a smooth transition allowing for a new concept to emerge as it slightly alters its content to fit into the existing ecology of ideas, in the other case the concepts demand a whole new conceptual ecosystem to attain everyday relevance – a relevance that will be countered in numerous situations due to its strangeness. In short, the epidemiology of representations is held in check by an “immunology of representations” that stabilizes clusters of concepts in structures of cross-reference.

I have presented this argument more fully in the now defunct journal Evolution and Cognition (http://kli.ac.at/publications-a.html?stuff/journal/contents)