Sales job postings tend to call for “self-motivated team players” who are “ethical” and “enthusiastic.” But anyone who has spent time in a sales organization knows that not every high performer fits that description. Some of the most successful salespeople display traits that most people would consider negative: a willingness to manipulate others, an inflated sense of self-importance, or a cold indifference to the consequences of their actions.
A study published in the Journal of Marketing examines how three specific personality traits, collectively known as the “dark triad,” affect salesperson performance. The research finds that these traits do not simply help or hurt performance across the board. Instead, their effects shift over time and depend on the social environment in which a salesperson works.
What is the dark triad, and why does it matter in sales?
The dark triad is a set of three personality traits that psychologists often study together because they tend to overlap and share a common thread of self-interested, exploitative behavior. The three traits are Machiavellianism (a tendency to manipulate others and view ethics as flexible), narcissism (an exaggerated sense of one’s own importance and a need for admiration), and psychopathy (a lack of empathy combined with impulsive, sometimes antisocial actions). In psychology, “psychopathy” here refers to a subclinical version of the trait, meaning it describes tendencies in the general population rather than a clinical diagnosis.
People in sales score higher on these traits than workers in almost every other profession, trailing only CEOs, lawyers, and celebrities, according to prior research. Despite this, most studies on what makes salespeople effective have focused on positive traits like adaptability and conscientiousness. Cinthia B. Satornino of the University of New Hampshire, along with co-authors Alexis Allen of the University of Kentucky, Huanhuan Shi and Willy Bolander of Texas A&M University, set out to fill that gap.
The team wanted to answer two questions. First, how do salespeople with dark triad traits perform over time compared with their peers? Second, how does the structure of social networks inside a company shape the performance of these individuals?
The theory: how dark personalities exploit uncertainty
The researchers built their investigation around a framework from communication science called uncertainty reduction theory, or URT. The basic idea is straightforward: when people first meet someone, they are uncertain about that person’s character. Over time, through observation and conversation, they gather information to reduce that uncertainty. If they learn that the person is trustworthy and worth collaborating with, they continue the relationship. If they discover the opposite, they pull away.
The researchers proposed that dark salespeople benefit when their colleagues have not yet figured out who they really are. During that window of uncertainty, coworkers give the dark salesperson the benefit of the doubt, share knowledge, and cooperate. But each dark triad trait differs in how visible and how severe its associated bad behavior is. Narcissists, for example, tend to be flashy and self-promoting, which makes their unpleasant side relatively easy to spot. Machiavellians, by contrast, operate quietly and strategically, keeping their manipulative behavior under the radar. Psychopaths can be charming at first, but their severe violations of social norms eventually become apparent.
These differences in visibility and severity, the researchers argued, should produce different performance patterns over time and in different social environments.
Study 1: tracking new hires over 18 months
The first study followed 82 newly hired salespeople at a U.S. insurance agency. Each salesperson completed a personality survey and then had their monthly sales tracked for up to 18 months. Because all participants started at the same time, the researchers could compare how their sales trajectories unfolded.
The analysis used a statistical technique called growth curve modeling, which traces the shape of each person’s performance over time. The researchers looked at how each dark triad trait was associated with changes in the rate of sales growth, relative to the average salesperson.
The results showed distinct patterns for each trait. Salespeople who scored high on psychopathy displayed faster-than-average sales growth during their first several months. But that advantage eroded quickly, and by around month 13, their growth had dropped below average and stayed there. The gains psychopathic salespeople made in the first half of the study shrank by roughly 90% in the second half.
Narcissism showed a similar directional pattern, with some initial advantage fading over time, but the differences from the average were not large enough to be statistically significant. In practical terms, narcissistic salespeople performed roughly at the same level as their peers throughout the observation period.
Machiavellianism told a very different story. Salespeople high in this trait started slowly, with below-average growth during their first several months. But their performance steadily improved, and by about month 16, their growth was significantly above average. By the end of the 18-month window, they had recouped about 88% of the ground they had lost early on.
Study 2: the role of workplace social networks
The second study shifted from a time-based lens to a structural one. The researchers collected survey data from 286 salespeople at a U.S. direct sales organization, then followed up 18 months later with 135 of those original respondents. Along with personality data, the team mapped the social network inside the company by asking each person to list the colleagues most important to their work.
The key network measure was something called “reach efficiency.” In simple terms, reach efficiency captures how easily information about a person can spread from their direct contacts to people further out in the network, people who are “friends of friends.” If reach efficiency is high, word travels fast. If it is low, information gets bottled up among the same small group of people.
The researchers then examined how reach efficiency shaped the relationship between each dark triad trait and sales performance. The results were striking. For salespeople high in Machiavellianism, high reach efficiency was associated with better performance. In other words, even when information could flow freely through the network, Machiavellians still came out ahead, likely because their subtle, covert style gave coworkers very little negative information to pass along.
For narcissists and psychopaths, the pattern reversed. When reach efficiency was low, meaning information traveled slowly, these salespeople performed well. But when reach efficiency was high, their performance dropped. In networks where information moved quickly, colleagues were more likely to learn about the narcissist’s self-promoting behavior or the psychopath’s more severe social violations, and cooperation with those individuals apparently declined as a result. The negative effect was more pronounced for psychopaths than for narcissists, consistent with the idea that more severe transgressions trigger faster and more damaging social consequences.
Overall, the model in Study 2 explained about 30% of the variation in sales performance, a notable figure given that traditional models focused on individual salesperson traits and customer interactions typically explain between 10% and 20%.
What this means for sales managers
The findings carry several practical implications. First, sales managers should recognize that dark personality traits are not uniformly harmful to performance. In certain conditions, they can be associated with above-average results. This does not mean managers should seek out these traits, but it does mean they should understand the dynamics at play.
Second, performance patterns can serve as warning signs. A new hire who dramatically outperforms peers in the first few months but then plateaus or declines may be exhibiting the classic psychopathic pattern: charm and cooperation that yield quick wins followed by a sharp falloff as colleagues pull away. Managers trained to recognize this trajectory can intervene earlier.
Third, the structure of internal social networks matters. Organizations that encourage open communication and create opportunities for employees to share information broadly may inadvertently speed up the process of exposing narcissistic or psychopathic salespeople. That exposure can protect the organization in the long run, even if it comes at the cost of short-term individual performance. The researchers suggest that facilitating what they call “prosocial organizational gossip,” essentially making it easy for colleagues to share observations about coworkers, can help managers identify problematic individuals more quickly.
Important caveats
Several limitations deserve attention. Both studies relied on relatively small samples, which limits the ability to detect more complex patterns, such as interactions between the three dark triad traits. The researchers also did not directly measure the flow of information through social networks; instead, they used the structure of those networks as a proxy for how easily information could travel. And while Study 1 tracked salespeople over 18 months, the longer-term trajectory remains unknown. It is possible, for instance, that the Machiavellian advantage eventually plateaus or reverses, but the data cannot show what happens beyond that window.
The studies also focused exclusively on individual-level performance. The effects of dark triad traits on team dynamics, customer relationships, and organizational culture were not examined. A high-performing Machiavellian might still cause significant harm to colleagues in ways that do not appear in individual sales numbers.
Despite these limitations, the research offers a window into a topic that sales organizations have long discussed informally but rarely studied with hard data: the real-world performance impact of the manipulative, self-centered, and impulsive personalities that are drawn to, and often thrive in, sales.
