California is full of psychopaths, but not as bad as D.C., study finds

A 1969 police sketch of the 'Zodiac Killer,' who killed people around the Bay Area and was never caught. Click through the gallery for a roundup of notorious American serial killers. A 1969 police sketch of the 'Zodiac Killer,' who killed people around the Bay Area and was never caught. Click through the gallery for a roundup of notorious American serial killers. Image 1 of / 20 Caption Close California is full of psychopaths, but not as bad as D.C., study finds 1 / 20 Back to Gallery

Ever feel like there's something sinister lurking behind the yoga-loving, avocado-eating facade of your fellow Californians? Now there's research to back you up.

California is among the two U.S. states with the highest concentration of psychopaths, according to a working study from Southern Methodist University released on the Social Science Research network this week. The study looks at trends in personality traits across areas (the study hasn't yet gone through the full peer review process, so take the findings with a grain of salt).

The only places with more psychopaths? Connecticut (thanks, hedge funds!) and, shocker, the District of Columbia. Other highly psychopathic states include New Jersey, New York and Wyoming, while West Virginia, Vermont and Tennessee are among the lease psychopathic states.

'The presence of psychopaths in District of Columbia is consistent with the conjecture found in Murphy (2016) that psychopaths are likely to be effective in the political sphere," the author writes.

The author, Ryan Murphy, combined the findings of two past papers, one that mapped distribution of the "big five" personality traits (neuroticism, conscientiousness, agreeableness, extraversion and openness to experience) across states and one that tracked which of those five personality traits most closely corresponded with psychopathy, to get the results.

The former paper found that there are three distinct clusters of personality traits in the United States — people are "friendly and conventional" in the Midwest and the South, "temperamental and uninhibited" in the Northeast and Texas, and "relaxed and creative" in the Southwest and Pacific Northwest.

Murphy's paper operates with the assumption that psychopathy exists on a spectrum — not as a binary category — and that it correlates with a combination of low neuroticism, high extraversion, low agreeableness and low conscientiousness.

Murphy found that the greater the share of a state's population that lives in dense urban areas, the higher the rate of psychopathy.

Other findings were more intuitive. Two things that correlate with a state with lots of psychopaths? High concentrations of journalists and lawyers.

Filipa Ioannou is an SFGATE staff writer. Email her at fioannou@sfchronicle.com and follow her on Twitter