Psychopathy and Machiavellianism are often described as identical twins in the realm of personality psychology, but when you track how people behave day-to-day, it becomes clear that they operate in very different ways. New research shows that while these hostile personality styles seem nearly indistinguishable on standard tests, they actually cause very different psychological states in everyday life. The findings were published in the Journal of Research in Personality.
These two personality styles belong to what psychologists call the “dark triad” of personality. The Dark Triad includes narcissism, psychopathy, and Machiavellianism. Each concept describes a set of adversarial traits characterized by a tendency to manipulate, exploit, or cause interpersonal harm to others.
Narcissism is defined by an exaggerated sense of self-importance and an extreme sense of entitlement. Machiavellianism, named after the Renaissance political philosopher Niccolo Machiavelli, centers on strategic manipulation, a cynical worldview, and long-term deceptive planning.
Psychopathy is characterized by severe impulsivity, thrill-seeking, and an extreme lack of remorse. Of the three, Machiavellianism and psychopathy share the most behavioral similarities. At their core, both traits are callous disregard for other people’s feelings.
Psychologists have long debated whether these latter two traits are actually separate concepts or just two different names for the same antisocial tendency. This naming problem is known in psychology as the “jungle fallacy.” This occurs when researchers mistakenly treat two identical concepts as completely different phenomena simply because they have different labels.
Standard self-report surveys often provide evidence of the jungle fallacy. When people sit down to answer traditional personality tests, those who score high on Machiavellianism almost always score high on psychopathy.
Behavioral experiments in laboratory settings often tell a completely different story. In the Lab Game, individuals with highly Machiavellian personalities exhibit a strong ability to delay gratification. They are very good at cheating without getting caught.
People who score high on psychopathic tendencies act more impulsively. They tend to break rules recklessly and lack the patience to implement long-term deceptive strategies. This contrast has left psychologists confused about how to properly measure and classify these dark personalities.
David Walczak, a psychology researcher at the University of Villa in Poland, led the new study along with Radosław Rogoza of the University of Villa and Daniel N. Jones of the University of Nevada. The researchers wanted to see if dynamically observing people over time could finally settle the redundancy debate.
To bridge the gap between artificial laboratory experiments and static personality tests, the research team focused on the differences between personality traits and personality states. Traits describe an individual’s basic personality over the course of their life. A state describes how a person acts or feels at a particular fleeting moment.
The researchers used experience sampling methods to track people in their natural environments. We recruited 317 adult participants from Poland. Participants downloaded a dedicated smartphone application and received a notification every night for 30 consecutive days.
Each day’s survey asked participants to rate the extent to which they agreed with statements that described their behavior over the past 24 hours. Questions were drawn directly from standard personality tests, but adapted to the daily timescale.
To measure Machiavellian status, participants rated statements such as “I kept a low profile to get my way” or “I avoided direct conflict with someone because that person might be useful in the future.” To measure psychotic status, they assessed statements such as “I was in a dangerous situation” or “I lost control of myself.”
The researchers then tested different mathematical models to see whether the responses grouped into one category or split into two different categories. When the team averaged all 30 days of responses to find each person’s long-term baseline, the results mirrored traditional personality tests.
At this broad baseline level, Machiavellianism and psychopathy overlap by more than 70%. They looked nearly identical. But when the researchers analyzed day-to-day variation within individuals, a very different pattern emerged.
In daily data, the overlap between the two states has plummeted to about 16%. The mathematical model confirmed that evaluating daily data as two distinct categories provided a much better fit than lumping them into a single category. This finding indicates that a person can experience a highly Machiavellian day without necessarily experiencing a highly psychopathic day.
The researchers also looked at how behavior on one day affected behavior the next day. They found a unidirectional relationship between the two personality states. An increase in strategic and manipulative behavior on Monday predicted an increase in impulsive and antisocial behavior on Tuesday.
The reverse was not true. An increase in psychopathic behavior on a given day did not predict an increase in Machiavellian behavior the next day. This directional relationship illustrates the role that risk and self-control play in dark personality expression.
Machiavellians perceive the environment in terms of situational risks. Machiavellian logic dictates that a person should suppress his antisocial impulses if he is likely to be arrested or punished. I’ll wait until the environment changes.
Psychopaths have poor impulse control and a general lack of fear. When a person is in a highly psychopathic state, they tend to act aggressively regardless of the consequences. Psychopathic behavior ignores environmental boundaries.
A unidirectional relationship suggests that Machiavellian restraint may eventually give way to psychotic outbursts once the environment is deemed safe or goals are achieved. A person who has been strategically planning for days may reach a point where they release their worst impulses.
The researchers noted several limitations in the study results that may affect how they are interpreted. The sample consisted mainly of young, educated women from Eastern European countries with moderate individualism. The lack of male participants may have limited the variability in the data, as men generally score higher on hostile personality tests.
Daily surveys were also limited to one check-in in the evening. This strict schedule means that the study may have missed rapid changes in personality state that occur hourly throughout the day. Future research may use more frequent daily check-ins to capture the changing nature of antisocial tendencies.
Researchers may also seek to measure precisely what kinds of environmental factors trigger transitions between these dark states. The current study provides initial evidence that although Machiavellianism and psychopathy share antisocial roots, their everyday expressions are entirely unique. To treat them as one and the same phenomenon is to ignore the strategic constraints that define Machiavellian ethos.
The study, “The (in)distinguishability of Machiavellianism and psychopathy? Discovering everyday dynamics” was authored by David Walczak, Radosław Rogoza, and Daniel N. Jones.

