There's a stereotype that people high in psychopathy tend to be charming, devious, and intelligent. It's common in fiction; from Hannibal Lecter to The Joker, on-screen psychopaths make up for their interpersonal deficits with nearly supernatural intelligence.
Is there any truth to it?
A new review posted on bioRxiv* sought an answer by analyzing the results of 187 studies about psychopathy and intelligence. The conclusion may be surprising: the relationship was weak, and negative. That is, people high in psychopathy tend to be slightly lower in intelligence.
A few caveats apply. First, we here at Cambridge Brain Sciences always emphasize that intelligence is more than one thing, so this analysis of overall intelligence is not as specific as it could be. Second, it's just a trend; there could still be psychopaths who beat the odds by having exceptional cognitive abilities. But most of them don't, which helps emphasize that psychopaths are not mythical stereotypes, but people with regular cognitive abilities alongside a troubling trait.
* Note: this analysis isn't peer-reviewed yet, so take the results with a grain of salt (or if you prefer, some fava beans and a nice chianti).
Image: Freddy Agurto Parra