There's some interesting personality research these days exploring the traits which make us good leaders or successful entrepreneurs. Staffan's Personality blog explores what we assume makes a good entrepreneur on a state-by-state basis.
The map above shows us where we are more likely to meet entrepreneurs, based on higher concentrations of extraversion, openness, and conscientiousness, and lower concentrations of agreeableness and neuroticism.
The map below shows us the extent to which people are actually engaged in entrepreneurial activity.
Assuming the personality research is correct, the real story these maps could tell is one of policy impacts. As Staffan points out, these maps are fairly crude representations of some pretty raw data. We probably have a good understanding of what legal and economic conditions foster the right environment for successful new business ventures, but there is still much work to be done to understand what it takes to make a successful entrepreneur -- other than hard work and determination.
Map of entrepreneurial activity. The darker the state, the more startups and self-employed. Also from Staffan's Personality Blog.