For this special Halloween Edition of my Research Roundup I’ll let a few more studies from the dark side of personality sneak in than usual. Enjoy!
1. People with psychopathic traits seem to enjoy being scared, and feeling invincible explains part of it.
In the first of two studies, 825 people (425 undergraduates and 400 online adults) watched a horror clip and rated how they felt. Higher psychopathic traits went with more positive reactions to the clip, with correlations around .26 to .32. A sense of invincibility accounted for the lower negative emotion, but it didn’t explain the extra excitement. A second study with 425 undergraduates replicated part of this, and boredom proneness, which the authors expected to matter, didn’t explain the enjoyment. The authors point toward dopamine-driven reward as the next place to look. I find the dark side interesting precisely because it turns out to be so ordinary in some of its ingredients. (Caveat: self-report, general-population samples rather than clinical ones, a three-minute clip rather than real danger, modest effect sizes, and not preregistered. Published online this month.)
2. Vulnerable narcissists struggle with their emotions. Grandiose narcissists mostly don’t.
This meta-analysis pooled 26 studies with 12,209 adults from the United States, Italy, Turkey, China, Iran, and Brazil, looking at how narcissism relates to trouble managing emotions. Across everything, the link was weak (r = .15). Split narcissism into its two faces, though, and the picture changes. Vulnerable narcissism, the insecure and hypersensitive kind, was moderately tied to emotional difficulties (r = .37). Grandiose narcissism, the bold and self-assured kind, showed essentially no link (r = .04). This is close to my heart, because my colleagues and I found the same split in our 2020 paper on the clinical correlates of vulnerable and grandiose narcissism: the vulnerable form carries much more of the distress. Lumping the two together hides most of what matters. (Caveat: every study was self-report and cross-sectional, half used only university students, and grandiose folks may simply be less aware of their own struggles.)
3. People with darker personalities say they want partners as dark as they are.
Researchers in Brazil asked 400 adults to rate their own Machiavellianism, psychopathy, and narcissism, and then how much they’d want each trait in a partner. The overlap was striking: correlations of about .59 for Machiavellianism, .66 for psychopathy, and .69 for narcissism, and they held after accounting for gender and sensation seeking. In a second part, people read short profiles of possible partners. A kind, prosocial profile got a 5.9 out of 7 for willingness to date. A dark-triad profile got 2.4, and adding a history of physical assault dropped it to about 1.5. Making that violent profile famous, rich, or good-looking didn’t help at all. So much for the idea that money or looks can launder a dangerous partner. (Caveat: stated preferences rather than actual partner choices, most people rated themselves very low on the dark traits, no attention checks, text-only profiles, and a convenience sample.)
4. Psychopathic traits show up alongside particular bacteria in the gut.
Here’s the spookiest one of the month. A team in Portugal and the UK recruited 200 community volunteers, measured their psychopathic traits, empathy, and anxiety, and collected stool, saliva, and blood samples. Overall gut diversity didn’t differ by psychopathy. But three gut bacteria, Allisonella, Prevotella, and Cloacibacillus evryensis, were more common in people higher in psychopathic traits, and one mouth bacterium, Treponema vincentii, was less common. Two stool molecules, glucose and taurine, were elevated in the group high in both psychopathy and anxiety, and both tracked with antisocial behavior and manipulation. I have no idea yet what to make of this, and I mean that in the fun way. (Caveat: a single snapshot, so diet and lifestyle could be shaping the microbiome rather than the other way around; community volunteers rather than clinical cases; self-reported traits; and the write-up didn’t report effect sizes. Published online in August.)
5. Intelligence tests predict job performance far less than the textbooks have claimed.
For decades the standard line was that general mental ability correlates at about .50 with how well people do their jobs. This meta-analysis pooled 212 independent samples and 109,396 workers from 1990 to 2022 and arrived at a corrected correlation of about .20, less than half the old benchmark. The tests did best in jobs heavy on hands-on, equipment-related demands, and they did essentially nothing for jobs heavy on cognitive complexity (r = -.04). People in the top fifth of test scores were about 1.6 times as likely as people in the bottom fifth to be rated above average. That’s a real edge and also a modest one. I’ve been saying since Ungifted that a single number can’t carry the weight we put on it, and here is a very large dataset agreeing. (Caveat: most studies relied on supervisor ratings, which are noisy; the authors’ explanations for the decline weren’t directly tested; and the corrections for range restriction are still debated. The paper was published online in August.)
6. Curious people collect the kinds of experiences that build cognitive reserve.
Researchers at Radboud University gave 106 adults between 40 and 85 a set of curiosity and openness questionnaires, plus a questionnaire on education, work, and leisure activities, which together make up what’s called cognitive reserve. The more curious people reported higher reserve from education and from leisure, and that held after accounting for age. Work complexity had no link to curiosity. And here’s the odd part: neither curiosity nor reserve was related to scores on three brief memory, executive function, and processing speed tests. I’ve spent a good chunk of my career on openness to experience, and I’d bet that curious people build the lives that keep a brain busy. This study can’t say which comes first, though. (Caveat: cross-sectional, a small and unusually bright sample with an average estimated IQ of 118, and reserve was self-reported. The paper came out in the summer.)
7. Creative drawing ability tracks the brain’s white matter wiring.
In this study from the University of Graz, 142 adults had 15 minutes to turn six line-and-shape fragments into a finished drawing while the researchers scored their creativity. Then the team imaged their white matter, the cabling that connects brain regions. Higher creativity went with higher white matter integrity across a wide network, including tracts that link visual regions at the back of the brain with deeper structures and the fibers that connect the two hemispheres. No tract showed the reverse pattern. The authors describe creative ideation as the product of many overlapping networks working together, with no single dominant connection behind it. That fits everything I believe about imagination. (Caveat: only drawing was tested, the effects were small to moderate, the design was cross-sectional, and intelligence wasn’t accounted for. Published online in August.)
Source: Creativity: a (white) matter of connectivity, Cerebral Cortex (2026)
8. Whether your best ideas are verbal or visual may depend on what your heart is doing.
A team in Austria had 157 students wear a portable ECG for five days and pinged them 12 times a day to come up with unusual uses for everyday objects (a verbal task) or to finish drawings from abstract shapes (a figural task). Across 6,930 valid heart rate variability readings, lower variability beforehand went with more original verbal ideas, and higher variability went with more original figural ones. It held after adjusting for age, gender, body mass index, activity, body position, and heart rate. People also came up with more original ideas at home than elsewhere. The body, it seems, tilts the mind toward certain kinds of creative work. (Caveat: observational, young university students, and stress, personality, and surroundings could be pulling on both measures. The paper dates to June.)
9. High-scoring women on cognitive tests get rated as more hostile by their teammates.
Across two studies, 432 U.S. business students and 394 employees at a financial company in China worked in small teams after taking cognitive ability tests. In both samples, women who scored higher were rated as more hostile by their teammates, which went along with more reported victimization and less help. In the Chinese sample they were also seen as less communal. For men the pattern ran the other way or was absent; in China, higher-scoring men were seen as less hostile and got more help. The authors call it a double bind. The effects were small, but the pattern bears on anyone who has watched a smart woman get called “intimidating.” (Caveat: correlational, the help and victimization reports were self-reported, the samples were pre-screened for ability, and the researchers never measured whether teammates thought of these women as smart. Published online in May.)
10. Trained practitioners of trance report that their sense of self loosens and their inner peace rises.
In a small pilot, 17 people who had practiced a self-induced cognitive trance for about 15 months recalled their last meal and then one of their most intense trance episodes, rating the sense of self in each. During trance, future-focused thoughts fell from 31.5 to 2.7 percent, the sense of authoring their own thoughts fell from 67 to 12 on a 100-point scale, and feeling distinct from their surroundings dropped while oneness with them rose from 28 to 76. Happiness rose from about 51 to 74, and inner peace from 44 to 75. Only two of the self-experience changes were significantly tied to happiness: feeling less at the center of the scene, and feeling less tied to one point in space. It’s a tiny study, and a very interesting window on what a looser sense of self feels like. (Caveat: 17 people, retrospective recall, an intense trance compared against an ordinary meal, and everyone trained at the same institute, with which a co-author is affiliated. Published online in August.)
That’s the ten for this month, from the shrinking power of IQ tests on the job to the bacteria living alongside psychopathic traits. Happy Halloween! Boo!
As always, I want to hear which one got under your skin, or just caught your eye. Tell me in the comments.