Other atheists sometimes confuse me with unexpected behaviour. I became an atheist because it is the only rational way to interpret the evidence. OK, so I'm technically agnostic, but a de facto atheist: as close to out-and-out atheism as makes no difference without being dogmatic about it. If enough evidence for the existence of god turned up, I'd change my mind, but I don't entertain the thought that any such evidence will be found.
Other atheists are doubtless inspired by other means. Some see the horrors carried out in religion's name and lose (or fail to develop) faith in the proposition that god is nevertheless somehow 'good'. Some hover around the 50/50 chance mark believing that we 'just can't know' whether god exists or not. Some have deeply personal reasons for not believing in god (he didn't come through for me when I needed him). I don't find any of these routes to atheism (or agnosticism) particularly rational, but the ones I really don't understand are the prove-god-exists-and-I-still-won't-believe-it variety.
We might be forgiven for calling these people 'dogmatic' or even 'fundamentalist' atheists (although technically, that's a contradiction) because they seem to share with the religious an unshakable belief in a position, regardless of whether evidence to the contrary might turn up. It's as though they have come to a rational conclusion (there is no god) through irrational means. Perhaps they just haven't thought about it very much, but this is in itself odd because we are talking about something rather important: a universe with a god in it would be very different from one without.
It's a slightly awkward segue, but there's an example of something similar happening here. This is an article on what is essentially an atheist website describing a hypothesis made by a couple of biologists from New Mexico, which suggests that the pattern of diversity seen in religions might have an evolutionary explanation to do with the spreading of disease. Religions tend to be divisive, they say, which limits contact between groups and therefore reduces vectors for disease transmission. They suggest that this might be why there tend to be more religions in tropical areas, where there are more diseases.
The hypothesis is not entirely implausible, although I have some serious objections to it. However, I only have a rather sketchy newspaper article to go on, since the paper is still in press and not available on line. I'll wait to see the paper before making a judgement about it.
However, the overwhelming majority of people commenting on the article (who are almost all atheists) are openly hostile to the hypothesis. They have decided in advance - regardless of whether there is any evidence - that it is wrong and have filled in the various blanks in the article themselves, in order to cast the hypothesis in as negative a light as possible, seemingly to justify their position. For example, the 'correlation is not causation' argument is used liberally. Well, sure, but until I find out otherwise, I'm prepared to give the two scientists and the peer reviewers the benefit of the doubt and assume they know that too. I'm prepared to guess that they are not suggesting that evidence of a correlation is evidence of causation. They are just throwing out a hypothesis and saying "OK, let's test it". That's how science is done.
I'm quite disgusted with most of the comments, actually, and with the lack of critical and scientific thinking behind them. Perhaps I shouldn't be. In fact, I should try to see this in a positive light: I don't get to insist that atheists be rational or that they come to atheism through rational means, and that's a good thing. If atheists were somehow forced to adopt a particular world view and set of ideals, then atheism would be a de facto religion and the world would be a poorer place for it. But having said that, I'm still disappointed by the response to this article and saddened to see a group of skeptics exhibiting exactly the sort of behaviour they despise in the religious.