Personality psychologists group the most socially harmful personality characteristics under the label “dark traits,” a cluster that includes manipulativeness, emotional coldness, inflated self-importance, and a willingness to exploit others. But the science of bad traits extends well beyond that clinical-sounding cluster into territory most people recognize in themselves: chronic procrastination, envy, greed, and the kind of rigid perfectionism that burns people out. What makes the research interesting is not just the catalog of unpleasant tendencies but how heritable they are, how they shift across a lifetime, and whether people can deliberately change them.
What Psychologists Mean by the Dark Triad
The most studied framework for bad traits in personality science is the Dark Triad: narcissism, Machiavellianism, and psychopathy. A foundational study found that while these three traits overlap positively, with correlations ranging from .25 to .50, they are not the same thing. Their distinctiveness becomes clearest when you look at how they relate to behavior and other personality measures, not just how people score on questionnaires.1Journal of Research in Personality. The Dark Triad of personality: Narcissism, Machiavellianism, and psychopathy Narcissism, for instance, stands apart from the other two in important ways: it correlates more strongly with extraversion and less strongly with the remaining dark traits than Machiavellianism and psychopathy correlate with each other.2Personality and Individual Differences. Psychopathy, Machiavellianism, and Narcissism in the Five-Factor Model and the HEXACO model of personality structure
In plain terms, narcissism is about grandiosity and entitlement. Machiavellianism is about strategic manipulation and cynicism. Psychopathy is about emotional detachment, impulsivity, and a deficit in empathy. A person can score high on one without scoring high on the others, which is why researchers treat them as related but distinct.
More recently, some researchers have proposed expanding the model to a Dark Tetrad by adding everyday sadism, the tendency to enjoy causing or witnessing suffering. Research supports sadism’s inclusion as a unique construct, though it shares conceptual ground with psychopathy.3Journal of Individual Differences. Subclinical Sadism and the Dark Triad A 2024 study exploring the four-trait model examined demographic, ideological, and personality correlates of what it called “Special” (narcissism), “Crafty” (Machiavellianism), “Wild” (psychopathy), and “Mean” (sadism), nicknames that, while a little blunt, capture the flavor of each trait better than their formal labels.4PubMed. Correlates of the Dark Tetrad
How Much of This Is Genetic
Twin studies offer a surprisingly clear answer. A behavioral genetic investigation of the Dark Triad and the Big Five personality traits found that all dark traits showed influences from both genetics and the individual’s unique (non-shared) environment. Heritability estimates ranged from .31 to .72, meaning that roughly a third to nearly three-quarters of the variation between people on these traits can be traced to genetic differences. One detail worth noting: Machiavellianism was the only dark trait that also showed the influence of shared environment, the kind of upbringing factors siblings in the same home have in common.5Personality and Individual Differences. A behavioral genetic investigation of the Dark Triad and the Big 5
The implication is that no one is born a blank slate when it comes to these tendencies. But the wide range in heritability, and the consistent role of non-shared environment, means that individual experiences like friendships, career setbacks, and personal choices still shape how strongly these traits express themselves. The genes load the gun; life pulls the trigger, or doesn’t.
Do Bad Traits Fade With Age
They often do, though the pattern depends on which trait you’re looking at. A longitudinal study tracking people from emerging adulthood into midlife found a significant downward trend for both Machiavellianism and psychopathy over the years, but no change in narcissism. The researchers described this as individuals “developing towards greater social desirability” over time.6European Journal of Personality. Codevelopment of the dark triad and depressiveness from emerging adulthood to midlife A separate seven-wave panel study from Japan added nuance: stability in these traits increased with age, with Machiavellianism showing the steepest rise in consistency over time. Narcissism and psychopathy were more fluid in younger people, becoming more locked in by the mid-sixties.7PubMed. Age-Graded Stability and Change in Dark Triad Traits: Seven-Wave Evidence From a Large Japanese Panel, With Big Five Benchmarks
So if you know someone in their twenties who seems manipulative or reckless, there is real reason to expect those tendencies will soften. But narcissism appears stubbornly persistent, and by late middle age, whichever level a person has settled into tends to stay put.
What the Brain Looks Like
Psychopathy, the darkest corner of the dark traits, has the most neuroimaging research behind it. A systematic review of brain-scanning studies found a consistent pattern of structural and functional differences. People high in psychopathic traits tend to have less gray matter in the prefrontal cortex, temporal regions, amygdala, and hippocampus. Functionally, psychopathy was linked to disruptions in the brain’s default mode network, which is involved in moral judgment and self-reflection. Reduced white-matter integrity in the tracts connecting the frontal and temporal lobes was associated with the emotional-detachment component of psychopathy, and dysfunction in mirror-neuron and theory-of-mind regions pointed to a persistent failure to integrate emotional information into decision-making.8PubMed Central. A Systematic Literature Review of Neuroimaging of Psychopathic Traits
None of this means psychopathy is purely a brain defect. The neuroimaging findings are correlational, and the heritability data confirm that environment plays a role too. But the brain differences are real and consistent enough to suggest that extreme emotional coldness is not simply a lifestyle choice.
Everyday Bad Traits Most People Recognize
Not every bad trait qualifies for the Dark Triad. Some of the most common ones sit closer to home: procrastination, envy, greed, and corrosive perfectionism. These may not sound as dramatic as psychopathy, but they cause real damage to well-being and relationships.
Procrastination
Chronic procrastination is not laziness. A conceptual review framed it as a low-resource way of avoiding difficult or unpleasant emotions tied to a task, with the risk of procrastination rising sharply in stressful contexts.9PubMed Central. Procrastination and Stress: A Conceptual Review of Why Context Matters Research also shows that people who struggle with managing their emotional reactions and controlling the focus of their thoughts are more prone to chronic procrastination, suggesting it is driven by poor emotion regulation rather than poor time management.10PubMed Central. Is poor control over thoughts and emotions related to a higher tendency to delay tasks?
Envy and Schadenfreude
Envy and the pleasure taken in someone else’s misfortune (schadenfreude) have been mapped to partially separable brain networks. Functional imaging research found that stronger envy corresponded to stronger activation in the anterior cingulate cortex, a region associated with social pain, while schadenfreude lit up the ventral striatum, a reward center. Critically, activity in the pain region during envy predicted activity in the reward region during schadenfreude, as if the brain were completing a cycle from suffering to satisfaction.11PubMed. When your gain is my pain and your pain is my gain: neural correlates of envy and schadenfreude A study using patients with brain lesions confirmed these associations and added that moral and legal dimensions of fairness recruited additional regions in the temporal and parietal cortex, showing that envy and schadenfreude are not just primitive emotional reflexes but involve complex social cognition.12PubMed Central. A lesion model of envy and Schadenfreude: legal, deservingness and moral dimensions as revealed by neurodegeneration
Greed
Dispositional greed, the chronic feeling that one never has enough, predicts real economic behavior. In laboratory games, greedy people allocated more money to themselves in dictator games and ultimatum games, and took more from a shared resource in dilemma scenarios.13PubMed. Dispositional greed Follow-up research found that greed predicted self-reported money investment, income aspirations, and risk-taking behavior beyond what the standard Big Five personality traits could account for, suggesting it is a standalone tendency worth tracking in its own right.14Journal of Research in Personality. The life and times of individuals scoring high and low on dispositional greed
How Bad Traits Show Up in Relationships
Dark traits do not stay contained inside the person who has them. They reshape relationships in predictable and often painful ways. When people high on Dark Triad traits end romantic relationships, they are more likely to use manipulative strategies and less likely to adopt approaches showing empathy or compassion for their partner.15Personality and Individual Differences. Dark Triad traits and relationship dissolution
Within ongoing relationships, the picture is just as complicated. Research on heterosexual couples using actor-partner modeling found that men’s Dark Triad traits had stronger effects on mate-retention behavior, both their own and their partner’s. Psychopathy had the strongest influence on controlling behaviors, and men’s dark traits tended to provoke more costly, surveillance-oriented mate-retention responses from their female partners.16PubMed Central. Dark Triad Traits and Mate Retention Behaviors in Romantic Couples
Research focusing specifically on women found that secondary psychopathy (the more anxious, emotionally volatile form) predicted both attachment anxiety and controlling behavior in relationships, including surveillance, threats, and control over a partner’s everyday routines. Machiavellianism in women predicted less constructive responses when a partner behaved badly, essentially a withdrawal from repair efforts.17Personality and Individual Differences. Dark triad traits and romantic relationship attachment, accommodation, and control The takeaway is that bad traits in one partner tend to erode the emotional safety that makes relationships work, and they do so through different mechanisms depending on the specific trait involved.
Bad Traits in the Workplace
Dark traits have attracted growing interest in organizational research over the past two decades, driven by how much damage they can do in professional settings. A comprehensive review described the Dark Triad as “three toxic and malevolent traits” linked to an array of organizational outcomes, from counterproductive work behavior and unethical decision-making to leadership styles that generate short-term results but long-term wreckage.18Annual Review of Organizational Psychology and Organizational Behavior. The Dark Triad and Workplace Behavior
One reason dark traits persist in organizations is that narcissism, in particular, can look like confidence and charisma during hiring and promotion processes. A person who dominates meetings and projects certainty can be mistaken for a strong leader. The problems surface later: narcissistic leaders often resist negative feedback, take excessive credit, and destabilize teams. Psychopathy in the workplace tends to show up as reckless risk-taking and a willingness to bend or break rules, while Machiavellianism is most visible in political maneuvering and alliance-building that serves the individual at the expense of the group.
Perfectionism, often viewed as a virtue in professional settings, has its own dark side. A meta-analysis found that “perfectionistic concerns,” the dimension of perfectionism driven by fear of mistakes and worry about others’ judgment, had a medium-to-large positive relationship with burnout.19PubMed. Multidimensional Perfectionism and Burnout: A Meta-Analysis Research among marriage and family therapists confirmed this, finding that both self-oriented and socially prescribed perfectionism correlated with higher levels of burnout and secondary traumatic stress.20PubMed Central. Are Perfectionistic Standards Associated with Burnout? The person who insists on flawless work and holds everyone to impossible standards is often the person most at risk of burning out completely.
Bad Traits Go Online
The internet provides a natural laboratory for observing bad traits because it lowers the social costs of antisocial behavior. Internet trolling, the deliberate posting of provocative or harmful content for amusement, correlates with all four traits in the Dark Tetrad.21PubMed Central. Troll story: The dark tetrad and online trolling revisited with a glance at humor But the traits contribute differently. Psychopathy and sadism drive active trolling most strongly, while narcissism is the strongest predictor of passive bystanderism, watching trolling unfold and tacitly encouraging it without directly participating.22Scientific Reports. The differential effect of psychopathy on active and bystander trolling behaviors
A surprising finding from experimental research is that anonymity does not always amplify the effect. In a social-media experiment, participants high in Dark Triad traits actually showed higher levels of cyber aggression under low-anonymity conditions than those with low dark traits, suggesting that for people with pronounced dark traits, the disinhibition is internal rather than situational. They do not need the cover of anonymity to behave badly.23PubMed. Investigating the Effects of Dark Triad and Anonymity on Exclusionary Cyber Aggression
Cultural Variation in Dark Traits
Bad traits are not evenly distributed across cultures, and the patterns are more interesting than simple “some countries are worse” narratives. A cross-cultural comparison of Dark Triad scores across five countries found that the specific trait that peaks varies by country: narcissism scored highest in Nigeria, psychopathy in Poland, and Machiavellianism in Peru.24Personality and Individual Differences. Dark and Light Triad: A cross-cultural comparison of network analysis in 5 countries A much larger analysis spanning 49 countries found that narcissism was especially sensitive to cultural systems. Countries with more hierarchical and socially embedded cultural structures showed higher narcissism scores. The study also revealed that sex differences in narcissism were larger in more developed societies: women in wealthier countries were less narcissistic relative to men than women in less developed countries.25PubMed. Country-level correlates of the Dark Triad traits in 49 countries
These findings push back against the idea that dark traits are fixed features of human nature expressed identically everywhere. Cultural incentive structures, power hierarchies, and economic conditions shape which bad traits a society cultivates or punishes.
Can People Actually Change Their Bad Traits
One of the more encouraging findings in recent personality science is that traits are not as fixed as researchers once believed. A randomized controlled trial involving over 1,500 participants tested a three-month digital personality-change intervention using a smartphone app. Participants who wanted to increase a positive trait showed significant self-reported changes, and, critically, so did participants who wanted to decrease a negative trait. The effect sizes were moderate, and observers like friends and family members also noticed the changes, which persisted for at least three months after the intervention ended.26PubMed Central. Changing personality traits with the help of a digital personality change intervention
This study focused on normal personality traits rather than the Dark Triad specifically, so it would be premature to assume the same approach works for psychopathy or Machiavellianism. But it does establish that personality change through deliberate effort is possible, measurable, and durable enough for other people to notice. The age-related decline in Machiavellianism and psychopathy described earlier suggests that life experience may accomplish something similar without formal intervention.
Why Bad Traits Might Exist in the First Place
From an evolutionary standpoint, the persistence of dark traits in human populations is a puzzle. If these tendencies are so destructive, why hasn’t natural selection weeded them out? One answer is that psychopathic traits may represent an adaptive strategy that trades long-term social reputation for short-term reproductive benefits. A review of the evidence framed psychopathy as a “fast life” strategy, potentially an adaptation to harsh or unpredictable early environments, with trade-offs between having more offspring and investing less in each one.27PubMed Central. Is it good to be bad? An evolutionary analysis of the adaptive potential of psychopathic traits A more recent theoretical model proposed that the shared core of dark traits, low honesty-humility, may have emerged as a strategy that works when it is rare in a population, gaining advantages through deception only as long as most other people remain trusting.28Evolution and Human Behavior. The origins of darkness: An evolutionary-developmental integration of Dark traits with the HEXACO
This frequency-dependent logic means dark traits are inherently self-limiting: the more common they become, the less they pay off, because everyone becomes suspicious. Evolution maintains them at a low but non-zero level in the population, which tracks with what personality researchers actually observe.
Dark Traits in Other Animals
Humans are not the only species with measurable variation in antisocial personality-like traits. A broad review of primate personality research identified dimensions like sociability, confidence/aggression, and fearfulness across multiple species, with aggression-related traits receiving substantial research attention.29PubMed. Personality in nonhuman primates: a review and evaluation of past research More recently, researchers have developed a psychopathy-like measure for chimpanzees and found that personality characteristics including disinhibition and meanness could be reliably rated by observers, even from facial photographs alone. Chimpanzees higher on disinhibition scored lower on conscientiousness and emotional stability, mirroring patterns seen in humans.30PubMed Central. Facial Expression of TIPI Personality and CHMP-Tri Psychopathy Traits in Chimpanzees (Pan troglodytes)
The existence of dark-trait-like variation in our closest living relatives suggests these tendencies are not cultural inventions. They appear to be built into the primate social toolkit, shaped by the same evolutionary pressures that gave us cooperation, empathy, and trust. Bad traits, in other words, may be as old as social living itself.