Narcissism and psychopathy are so fascinating because they can simultaneously help individual leaders advance their careers while hurting the people and organizations they lead.

Why we love psychopaths: Let us now turn our attention to the other major dark-side trait. Psychopathy is often discussed in connection with leadership, particularly when it comes to famous political and business leaders. Unlike narcissism, which is widespread, psychopathy is rare. And yet few toxic character traits have attracted as much public fascination and media attention as psychopathy has—even though only about 1 percent of the general population is thought to have psychopathic tendencies.

Because of the abstract nature of leadership, charisma often ends up being a convenient proxy for it, especially in the absence of other clear indicators. However, it is a poor proxy, and we ignore the true, objective indicators of leadership talent and performance at our peril.

Dark side traits can be divided into three groups. The first group is the distancing traits—obvious turnoffs that push leaders away from other people. Being highly excitable and moody has this effect, for instance; or having a deeply skeptical, cynical outlook, which makes it hard to build trust. Another example is leisurely passive-aggressiveness—pretending to have a relaxed, polite attitude while actually resisting cooperation or even engaging in backstabbing.

The second group of traits has, in contrast, seductive qualities; they are geared to draw people in. These traits are often found in assertive, charismatic leaders, who gather followers or gain influence with bosses through their ability to manage up. Narcissism and psychopathy are in this group.

The third group contains ingratiating traits, which can have a positive connotation in followers but rarely do in leaders. Someone who is diligent, for instance, may try to impress the boss with meticulous attention to detail, but this attention can also translate into preoccupation with petty matters or micromanagement of the person’s own direct reports. Someone who is dutiful and eager to please those in authority can easily become too submissive.

More precisely, traits such as confidence, narcissism, psychopathy, and charisma advance individuals’ careers without improving the success of the groups they lead. Clearly, we would be better off if we sifted out individuals with such traits, as opposed to rewarding them. The success of teams and organizations is more important than an individual’s personal success, especially when individual victory harms the rest of the group.