I suspect a lot of bloggers may be introverts, because blogging is great if you like to sit in front of the internet all day. If not for my aversion to specializing in one subject, I probably would have been an academic historian, because I think it would have suited me to work in libraries back before there was an internet.
So I asked Cambridge personality psychologist Jason Rentfrow about it:
I would be inclined to think that Openness would be a big predictor of blogging because it's related to curiosity and reflection... But just as my work on music and entertainment preferences indicates that personality is related to preferences for particular content, I would imagine personality is related to the content of people's blogs.
Rentfrow sent along a link to this study on bloggers and personality:
We examined whether the Big Five personality traits predicted blogging. The results of two studies indicate that people who are high in openness to new experience and high in neuroticism are likely to be bloggers. Additionally, neuroticism was moderated by gender indicating that women who are high in neuroticism are more likely to be bloggers... The results indicate that personality factors impact the likelihood of being a blogger and have implications for understanding those who blog.
As for Rauch, his being wary of over-specialization leads the armchair psychologist in me to believe he is likely to be high in openness-to-experience as well as being an introvert. Highly creative people frequently share these sorts of personality traits. Like The Economist, I'd place him way up on the spectrum of creative people, which the leading psychologist of creativity describes this way.