6 Fatal Flaws That Kill A Leader’s Effectiveness

You Don’t Have to Be Perfect to Be a Great Leader

We often admire great leaders despite knowing they have flaws. Their stories remind us of an important truth: perfection isn’t a prerequisite for leadership excellence.

In our own research, my colleague Joe Folkman and I found the same to be true. Minor weaknesses typically don’t hold leaders back. Our research highlighted, however, that there was a difference between mere weaknesses and what we call fatal flaws.  A fatal flaw isn’t just a shortcoming—it’s a significant liability. It creates such a negative impression that it overshadows strengths and prevents a leader from being seen as truly effective. In fact, no one with a fatal flaw ever appeared among the top-tier leaders in our data.

That distinction came up when we were certifying a group of coaches who support a leading university’s Executive Education program. We explained our definition of a fatal flaw as a competency on which a leader had a score at or below the 10th percentile. One of the coaches posed an excellent question, “On which competencies do fatal flaws most frequently occur?”

A Health Analogy for Leadership Failure

Globally, six diseases are responsible for a large percentage of all deaths. Heart disease and stroke account for more than half of all deaths, followed by pulmonary diseases, Alzheimer’s, cancer, and diabetes.  If the goal is to diminish mortality, these are the diseases on which to focus.

What are the comparable areas of leadership behavior that account for the greatest numbers of leadership failures?

The Most Common Causes of Leadership Failure

To answer that, we analyzed data from over 87,000 leaders across the globe, each evaluated by an average of 13 peers, managers, direct reports, and others through a 360-degree assessment.

In previous research, we defined a profound strength as a competency rated at or above the 90th percentile. We applied the same logic at the other end of the scale. We identified those behaviors at or below the 10th percentile as fatal flaws. We calculated the 10th percentile mean score for each of the competencies we measured and then created an overall 10th percentile average score.

Using this 10th percentile average score as the general cut-off score for fatal flaws, we then identified which competencies had the highest and lowest frequency of people in this fatal flaw range.

What was the most common fatal flaw among all leaders? The answer was “Inspiring and Motivating People to High Performance.”

Check out the latest episodes of The 90th Percentile: An Unconventional Leadership Podcast 

Impact of Fixing Fatal Flaws

There was a natural breakpoint in the data after the top 6 competencies. Interestingly, five of the top six fatal flaws were interpersonal in nature—not technical expertise, strategic thinking, or even the ability to get results. What derails most leaders is how they interact with others.

Is this surprising? Consider this: A study done with Bank of America found that 39% of millennials admitted to interacting more with their smartphone than the actual people in their lives. At the end of the day, many leaders have been so focused inward that they forgot their main job was to focus outward on those they are supposed to lead.

Here’s the good news:
Fatal flaws don’t have to be fatal.

In fact, more than 60% of leaders who received feedback about their fatal flaws were able to make a significant positive change. In a study with 1,469 leaders with fatal flaws, we found that by working to improve these flaws they were able to move their overall leadership effectiveness rating from the 18th percentile to the 46th percentile.

How to Improve The Six Most Common Fatal Flaws in Leaders

Inspires and Motivates. The most common fatal flaw is the inability to inspire and motivate others. Roughly 1 in 5 leaders struggle significantly in this area. Most leaders have learned how to drive for results. We call that push. Pushing is an effective way to make sure that others get work done: setting deadlines, holding others accountable, etc. Pushing works, but it only goes so far.

What’s often missing is thee ability to pull—to inspire and motivate others by creating excitement and meaning around work. Inspiring leaders don’t just tell people what to do; they create a sense of purpose that pulls people forward.

Not everyone feels that they can be inspiring.  They jokingly admit that they do not want to be a cheerleader. But with a fatal flaw in inspiring and motivating, leaders risk draining energy from their teams rather than refueling it.

The truth is, it’s possible for leaders to learn to be more inspiring. Leaders can:

• bring positive emotions to work
• make a deliberate effort to connect with other team members
• communicate consistently and transparently
• create meaningful development opportunities for others

These actions may seem small, but together, they create the kind of energy that motivates people to do their best work—not because they have to, but because they want to.

Practices Self-Development. The second most common fatal flaw is one that’s completely within a leader’s control. One of the most effective—and underused—strategies for growth is simply asking for feedback. Yet many leaders avoid it, fearing it makes them look weak or insecure.

In reality, the opposite is true.

Asking for feedback signals confidence and courage. It shows you’re open to learning and that you respect the insights of others. And when people feel respected, they’re more likely to offer helpful, honest input that accelerates your growth.

Leaders who actively. seek feedback are far more likely to catch blind spots, course-correct early, and develop faster. Interestingly, younger employees are more likely to ask for feedback, but that declines as the decades go by. Practicing self-development isn’t about perfection—it’s about progress. And it starts with the humility to ask, “What can I do better?”

Teamwork and Collaboration. Have you ever been part of a great team? Have you ever been in a group where it was fun to just be there and be included? You worked hard because the team worked hard. On the other hand, have you ever been on a difficult team? The difference is huge. Being on a great team improves morale, productivity, quality and engagement. Some leaders can build a good team, but then decide they are in competition with other teams in the company. They hoard resources, resist communication and fail to cooperate. That kind of behavior makes the organization less successful. Leaders can learn how to build a positive team and cooperate with other teams.

Develops Others. Employee surveys show that one of the most sought-after rewards of a job is the opportunity to develop and learn a new skill. Development transforms a job into a career. Yet many leaders, feeling overwhelmed by their own responsibilities, hesitate to invest in developing others. Leaders who actively seek opportunities to develop their direct reports create a culture of growth and increase both engagement and the productivity of the team.

Communicates Powerfully. Communication is one of the easiest skills to improve. Our research revealed that when comparing pre-test to post-test results, the largest improvement came in the area of communication. Many leaders fall short simply because they don’t put in the effort to keep others informed, share information accurately, or follow up consistently. Moving from a fatal flaw in communication to an average level takes intentional effort and practice, but small changes are highly visible and quickly noticed by others.

Two fundamental skills can make a profound improvement in communication:

1. Asking good questions — showing curiosity and engagement
2. Listening well — which goes far beyond silence. It involves actively working to understand what the other person is thinking and feeling, and helping them express those thoughts clearly and effectively.

Mastering these skills creates clarity, trust, and connection—key ingredients for leadership success.

Builds Relationships. Some leaders have a difficult time building and maintaining positive relationships with others. They may keep others at arm’s length—believing that being too friendly will undermine their authority or open the door to being taken advantage of. What suffers the most with poor relationships is trust. Distrust erodes almost every other aspect of leadership. Leaders who take time to connect on a human level foster loyalty, openness, and mutual respect. Learning the fundamentals of how to build a positive, trusting relationship with others is a skill that will help people in every aspect of their lives.

If you are a leader who struggles with one of these six common fatal flaws, ask for help. Even small, incremental improvements can make a significant positive impact on how a leader is perceived by others.  On the aggregate responses from a manager, several peers, and direct reports; if the responses on a 5-point scale are increased by ½ of a point, the person moves from being at the 10^thpercentile to the 50^thpercentile. That’s a dramatic shift—driven by relatively modest changes in behavior.

The bottom line? Fatal flaws are fixable. And for leaders willing to put in the effort, the payoff isn’t just better ratings—it’s better relationships, stronger teams, and more lasting impact.

-Jack Zenger