There are Red States and Blue States. The three blue states of the Pacific coast constitute the Left Coast. For Colin Woodward, Yankeedom comprises both New England and the Great Lakes. If you’re into accessories, there’s the Bible Belt, the Rust Belt, and the Stroke Belt.

In the Journal of Personality and Social Psychology (online preview Oct. 2013) Rentfrow et al argue that the social, cultural and political divisions in the US actually reflect more fundamental personality/regional divisions. Using cluster analysis on data from 5 published sample surveys, they split the country up into three personality types:

• Friendly and Conventional (mostly the Midwest and upper South)
• Relaxed and Creative (the West Coast)
• Temperamental and Uninhibited (the Northeast)

There are some interesting statistical issues (and some answers) embedded in the paper. Why three clusters, not four or five? Four of the surveys were based on respondent self-selection, the fifth (much smaller) on random digit dialing (RDD). How did the RDD survey results compare to the self-selected surveys?

This is a paper that is likely to get some press – check it out at http://www.apa.org/pubs/journals/releases/psp-a0034434.pdf