Here's a study described in second hand by Richard Florida, one of my favorite sociologists and a big proponent of the "creative economy." Midwesterners are friendly but conventional, West Coasters are relaxed and creative, and Northeasterners are temperamental, uninhibited, and just darn neurotic.
The study draws on a wide body of data and information collected from five separate internet survey samples over 12 years, covering 1.5 million individuals across the 48 contiguous states. The primary objective of the study, according to the researchers, was to map the "psychological topography of the United States," composed of "geographically coherent psychological regions." To do so, they used a statistical technique known as "cluster analysis" to examine how five major personality traits – openness, conscientiousness, extroversion, agreeableness and neuroticism – are distributed and cluster across American states and regions.
The study identifies three main regional types: friendly and conventional, relaxed and creative, and temperamental and uninhibited. The maps below, from the study, show how these line up across America's states.