Of course, it depends more on the individuals involved than anything else, but I would say that a non-negligible percentage of rationalists are unwilling to question gender biases (and in fact, many get defensive because they prefer to consider themselves rational and non-sexist, and then in their defensiveness, fail to examine their biases). This is common enough that the geek feminist blog Restructure has a whole post called The Myth Of White Male Geek Rationality: http://restructure.wordpress.com/2010/08/23/myth-of-white-male-geek-rationality/