The character of Hannibal Lecter has perpetuated the myth that psychopaths are vastly intelligent people, but this may not be so. All Action EMPICS Entertainment/PAimages

Manipulative, callous, and intelligent: This is how most people think of psychopaths. But are they really as clever as we assume? It seems that new research has cast doubt on the smarts of psychopaths, and suggests instead that they may even possess lower than average levels of intelligence.

Reinforced by the most famous of fictional psychopaths, the idea that these remorseless, dishonest, and charming people are also gifted with brains was embodied in the supremely intelligent Dr Hannibal Lecter. In fact, it is this flesh-eating villain that has given his name to what is now known by psychologists as the “Hannibal Lecter myth.”

Over the history of studying psychopaths and their general characteristics, the degree of intelligence that they show has been contentious, and frequently debated between psychologists. But recent research has been gathering evidence that the earlier studies that equated brains with psychopathy may have been biased from the beginning, by focusing primarily on subjects from well educated, middle and upper class sections of society.

Confounded by the fact that they are often manipulative and display superficial charm, it gave credence to the idea that these social anomalies were more intelligent than most. But new research, currently in preprint, seems to support that this is probably not the case, and in actual fact, the opposite is seemingly true – psychopaths may be less intelligent than average.

The research is a meta-analysis of 97 previous studies that have looked at how intelligence relates to psychopathy. The studies involved over 9,000 participants, including both those who are currently in prison and those who are experiencing successful careers. They found that those who scored higher for psychopathic traits tended to score lower on measures of IQ, producing a small but significant correlation.

They note that there is a lot of variation both within intelligence and psychopathy, including that there is even potential evidence for subdivisions within the disorder itself. Research suggests that there are primary and secondary psychopaths, with some indicating that the differences between the two may relate to how inhibited they are, and the authors of this latest study suggest that it is possible that the levels of intelligence vary between these two groups.

Changing how psychopaths are perceived could have implications not only for the general public, but also for the criminal justice system, which may alter how they are treated, and what sentences they receive.