Simply put, it’s impossible to build a great company if you have a destructive leadership style.

Every good-to-great transition in our research began with a Level 5 leader who motivated people more with inspired standards than inspiring personality. Every 10x entrepreneurial success in our research had founders and leaders who, while sometimes colorful characters, never confused leadership with personality; they were utterly obsessed with making the company truly great and ensuring it endured beyond themselves.

To be clear, many charismatic people are neither psychopathic nor narcissistic, in the same way that many psychopathic and narcissistic people have absolutely no charisma. But when these darkside traits are lubricated with charisma, they can make leaders pretty lethal. The more we rely on charisma as a marker of leadership potential, the more we risk ending up with toxic leaders who are exploiting their charms and influence to grab power and manipulate their followers.

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.

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.