If you are an atheist living in the U.K., you might have noticed that your local secular activist groups seem to attract more men than women. What might this mean? Does this mean that the secular movement in the U.K. is "hostile to women" like some have suggested it is here in the U.S.? Are women refusing to join such groups because of rampant sexism and misogyny? I suppose that is possible, but a recent study from the UCL Institute of Education offers at least one alternative explanation: we may see more men in the secular movement because men are more likely to identify themselves as not believing in gods.
According to the National Secular Society, the study sampled the 1970 British Cohort Study, meaning that it included roughly 9,000 Britons in their 40s. This is an interesting age range since we tend to hear far more about younger samples. Using this sample, they found that men were about twice as likely to identify themselves as atheists as were women. If this is the case, wouldn't we have to expect to see more men involved in secular activism?
A base rate fallacy is a common error in thinking where one tends to ignore base rate information (e.g., the large gender difference in god belief reflected in this study) and focuses instead on a specific instance (e.g., my local secular activist group has way more men than women). You can find some more examples of base rate fallacies on Wikipedia that illustrate how this sort of error often leads us astray. For those of us who seek to be more rational, this is a common error of which we should be aware.
Before we conclude that anything short of a 50-50 gender split is evidence of sexism or misogyny, it might be helpful to take a look at the numbers and find out whether there are meaningful sex differences. If we find that women and men are equally likely to identify themselves as atheists, to view secular activism as important, and to join activist groups, we'd have a strong argument for being more concerned about there being more men than women in these groups. On the other hand, if we find that men are far more likely to identify as atheists, view secular activism as important, and join activist groups, then we should not be surprised if group membership reflects these differences.
Of course, none of this is an excuse to ignore the experience of women in secular activist groups. Even if women are few in number because they are less likely to be atheists, to embrace secular activism, and/or to join activist groups, these groups benefit from their presence. Thus, it is important that women feel accepted and have a voice in these groups even if they are outnumbered.