Our large cryonicist population is probably biasing us towards cryonicist ideas. Our large computer scientist population is almost certainly biasing us towards explanations of consciousness/intelligence which rely on computational metaphors. Our large, outspoken atheist contingent probably biases us away from conveying positive attitudes towards religion, lest we be publicly ridiculed. Are these biases problematic too?
Social groups form based on shared ideas. Of course they will be biased! I think most of us would be unhappy in a totally unbiased LessWrong, because we'd be so busy debating things like theism vs. atheism that we'd have no time to delve into the finer-grained implications of our philosophical worldview.
I feel like you're conflating "unbiased" with "zero-knowledge". Flat-earthism is not an accepted viewpoint here, but that's not because we're biased against flat-earthism, it's just that flat-earthism is stupid. If it turned out that flat-earthers on average were happier and better at getting things done than other people, and if we failed to acknowledge that because flat-earthism is stupid, then that would indicate a harmful bias against flat-earthism.
If the reason we don't debate theism vs. atheism is mere bias, then we're all fooling...
Summary: Current social psychology research is probably on average compromised by political bias leftward. Conservative researchers are likely discriminated against in at least this field. More importantly papers and research that does not fit a liberal perspective faces greater barriers and burdens.
An article in the online publication inside higher ed on a survey on anti-conservative bias among social psychologists.
The link above is worth following. The problems that arise remind me of the situation with academic and our own ethics in light of this paper.
I can't help but think that self-assessments are probably too generous. For predictive power of how an individual behaves when the behaviour in question is undesirable, I'm more likely to take their estimate of how "colleagues" behave than their estimate of how they personally do.
This shouldn't be surprising to hear since to quote CharlieSheen: "we even have LW posters who have in academia personally experienced discrimination and harassment because of their right wing politics."
While I can see Lammers' point that this as disturbing from a fairness perspective to people grinding their way through academia and should serve as warning for right wing LessWrong readers working through the system, I find the issue of how this our heavy reliance on academia for our map of reality might lead to us inheriting such distortions of the map of reality much more concerning. Overall in light of this if a widely accepted conclusion from social psychology favours a "right wing" perspective it is more likely to be correct than if no such biases against such perspectives existed. Conclusions that favour "left wing" perspective are also somewhat less likely to be true than if no such biases existed. We should update accordingly.
I also think there are reasons to think we may have similar problems on this site.