Some people feel attracted to manipulators and even to violent criminals. Scientists from Brazil decided to find out why this happens. The results of the study were published in the journal Evolution and Human Behavior.
The survey involved 400 people aged 18 to 60 (average age about 28). Among them were 193 women, 176 men and 31 people who identified as non-binary, transgender women (travesti) or did not indicate their sex. Because these groups were small, they were excluded from the analysis of gender differences, leaving 369 participants.
Participants filled out online questionnaires rating their personality traits on the "Dark Triad" scale, a set of three qualities: narcissism (self-love and a need for admiration), Machiavellianism (a tendency to manipulate and deceive for gain) and psychopathy (callousness, impulsivity, lack of empathy). They were also asked how attractive these traits are in a potential partner. In addition, their tendency toward risk-taking and sensation-seeking, including sexual sensation-seeking, was measured.
In the second part of the experiment, participants were randomly shown one of six short text portraits of a hypothetical partner (without indicating sex, age or race). The first described a kind and responsive person. The second described a manipulator with no criminal past. The third described the same kind of manipulator, but one who had committed physical violence. The remaining three added fame, wealth or outstanding appearance to the portrait of the criminal. After that, participants had to rate their willingness to enter into short-term or long-term relationships on a scale from 1 (not at all willing) to 7 (completely willing).
It turned out that the higher a person's own scores on dark traits, the more desirable they considered the same qualities in a partner. The correlation (a statistical association that by itself does not prove causation) was about 0.59 for Machiavellianism, 0.66 for psychopathy and 0.69 for narcissism. This association held even after adjusting for sex and risk-taking. The findings are consistent with the homogamy hypothesis, the tendency to choose partners similar to oneself.
The "side attractiveness" hypothesis, however, was not confirmed. The kind and responsive person received an average of 5.92 points out of 7, the highest result. The manipulator with no criminal past received 2.40. The criminal who had committed violence received 1.52. Adding fame, wealth or beauty barely changed the picture: 1.46, 1.49 and 1.60 respectively. There was no statistically significant difference from the "ordinary" criminal.
"Although some people are attracted to antisocial traits and criminals, prosociality (kindness and willingness to help) remains far more desirable in partner choice," explained lead author Catarina P. da Silva.
The study has limitations. Most participants rated themselves and their ideal partner very low on the dark traits scale (on average from 1.58 to 2.45 out of 5), which could have artificially inflated the similarity of the ratings. Brief questionnaires were used without attention checks, and the sample was a convenience sample of educated internet users from Brazil, which does not reflect the entire population. In addition, the descriptions of beauty, wealth and fame in the text may not have evoked the same emotions as real photographs or meetings.
The authors hope that further work will study other social environments and types of crimes to understand whether preferences change.