I hear you saying that women and men are measurably different in their political and social views; and that whites, blacks, Hispanics, and Asians are likewise different in their views.
(I broadly agree, although I think you exaggerate on the political-party issue specifically — and indeed to the point of logical inconsistency. You note that 45% of men voted for a center-left candidate, and then say that "women support the left and men do not". These statements are logical contraries) and cannot both be true.)
However then I hear you saying that there is more intellectual diversity among "an exclusively middle class white male group" than among a demographically diverse group. This statement is a direct contradiction of your (correct) point that different demographic groups are measurably different in their views.
Of course, you've read my above comment and so you already know that I think there is a good reason that reasonable people from different backgrounds can arrive at different views; namely that they are in possession of different information about the world.
There would likely be more intellectual diversity among a demographically diverse group randomly selected from the general population than there would be among a homogenous group randomly selected from one demographic within that population. However, if the demographically homogenous group was comprised of specialists of diverse fields of study, they would likely be more intellectually diverse than the demographically diverse group selected from the general population.
What I said was, "There is likely to be more intellectual diversity between an exc...
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.