Among lurkers, the average feminism score was 3.84. Among people who had posted something - whether a post on Main, a post in Discussion, or a comment, the average feminism score was 3.8. A t-test failed to reveal any significant difference between the two (p = .49). So there is no difference between lurkers and posters in feminism score.
Among people who have never posted a top-level article in Main, the average feminism score is 3.84. Among people who have posted top-level articles in Main, the average feminism score is 3.47. A t-test found a significant difference (p < .01). So top-level posters were slightly less feminist than the Less Wrong average. However, the average feminism of top-level posters (3.47) is still significantly higher than the average feminism among women (3.1).
I update in the direction that the model of people I form based on LW comments is pretty inaccurate.
A long blog post explains why the author, a feminist, is not comfortable with the rationalist community despite thinking it is "super cool and interesting". It's directed specifically at Yvain, but it's probably general enough to be of some interest here.
http://apophemi.wordpress.com/2014/01/04/why-im-not-on-the-rationalist-masterlist/
I'm not sure if I can summarize this fairly but the main thrust seems to be that we are overly willing to entertain offensive/taboo/hurtful ideas and this drives off many types of people. Here's a quote:
The author perceives a link between LW type open discourse and danger to minority groups. I'm not sure whether that's true or not. Take race. Many LWers are willing to entertain ideas about the existence and possible importance of average group differences in psychological traits. So, maybe LWers are racists. But they're racists who continually obsess over optimizing their philanthropic contributions to African charities. So, maybe not racists in a dangerous way?
An overly rosy view, perhaps, and I don't want to deny the reality of the blogger's experience. Clearly, the person is intelligent and attracted to some aspects of LW discourse while turned off by other aspects.