Studying the Effect of Search Personalization

Via SearchBlog, Informit.com recently published an article by Eric Goldman which claimed that personalized search would largely protect search engines from their algorithmic biases, but is anyone trying to study the effects that personalized search may have on society?

Does anyone think that personalization could cause people to become more intolerant by reinforcing the worst parts of their biases, especially as search engines aim to target more ad types and host more and more media and are driven by conversion? And does it matter that search engines may act as word police by making certain words or phrases unprofitable to publish?