Learning is increasing. The Financial Times reported in May that enrollment increases in business school short courses have caused the publication to increase the number of schools included in its annual executive education ranking.

The problem is learners don’t seem to have time to improve themselves. If we listen to proponents of strengths-based learning, we likely shouldn’t bother. We should all just get down to doing what we each do best.

Last year, Ekaterina Walter wrote “Four Essentials of Strength-based Leadership” in the Aug. 27 issue of Forbes, describing unleashing a “fervent army of brand evangelists” if we would just “stop trying to ‘fix’ our employees and rather focus on their strengths and their passions.”

However, with this approach everyone’s passion could start to get in the way of management, collaboration, innovation and leadership. Steve Hanna, vice president and chief information officer with Kennametal Inc., a supplier of tooling and industrial materials, is an advocate for continuous development, and is resistant to adopting the strengths-based practice. Hanna is directly involved in Kennametal’s corporate learning process.

“When we rely too much on what we already do well, people become myopic in their silos,” he said. “They start missing the connectivity. But the value of the enterprise is the connectivity. Individually, you’re not going to the next level if you don’t fix things you’re weak in.”

Strengths-only approaches are valid for certain situations, such as those in which people are pretty much where they plan to be in their careers. However, a single focus on strength is shortsighted for people who want to advance and for organizations that require succession plans.

Hervé Coyco started his career at Michelin as an engineer designing energy infrastructures for new factories and gradually moved to managerial positions, heading a team of 60 engineers. Over one weekend he accepted a major new role, president of the largest division, and found himself leading a team of 60,000.

“All of a sudden I realized that what had been strengths were becoming obstacles,” Coyco said. “When I was running a team of 60 engineers, I was able to control every single technical decision of my team. But trying to control everything with 60,000 became a weakness that would lead to micromanagement.”

Learning by Definition
Working to be effective with more people, discovering negative tendencies that prevent leaders from persuading colleagues and working on self-improvement all require examining weaknesses.

Hanna said improved teamwork is a natural outcome of well-rounded development, because engendering such self-awareness increases awareness of team members. “Everyone as an individual has the responsibility for continuous improvement, and every single day you should be working on something for total capabilities. As you become a more complete player, you’re more valuable.”

Starting as an hourly worker in manufacturing, Hanna had to master job skills and people skills he said he never knew that he’d need. Kennametal offered him other jobs in the company, and he said he’s a better CIO because of all those experiences. “I continue to grow this way.”

At Michelin, Coyco accepted feedback from his staff and learned to delegate what he had once controlled. His dramatic increase in responsibility forced Coyco out of his comfort zone and onto a successful leadership career. “There is something lazy about always playing to your strengths because it’s a way of avoiding the pain of forcing yourself to develop new capabilities,” he said.

The strengths approach is not likely to bring the organization generalist leaders who can lead in a variety of situations, for several reasons.

Strengths are relative. “It Depends on What You Mean by a Strength” is the title of a chapter by Guangrong Dai, Robert Eichinger and King Yii Tang from the book “The Perils of Accentuating the Positive.” In their analysis of data compiled from 360-degree surveys compiled between 2005 and 2007 of 1,857 people from 20 different companies across a range of business categories, the authors found that only 39 percent had five or more of the 67 vital competencies listed in the instrument. And 26 percent of participants had none.

According to the trio, any organization is likely to find itself short of people who have the most desired competencies if it relies solely on strengths. They also suggest that even if a leader is strong in required competencies, it’s important to consider where the individual ranks with everyone else. Being merely equal to or lower-rated than any peer on any strength is not a competitive advantage for the individual.

Strengths do matter in learning and development, but even strengths need improvement. And relying too much on strengths can limit an employee’s career prospects.

People overestimate themselves.In one-to-five scales of self-assessment, there are often far more fours and fives among American learners than those of other nations. In Europe and Asia, classrooms are more self-critical, with a lot of threes and fours. Conversely, when discussing weaknesses, people tend to underestimate.

Ask any 10 people and often 90 percent think they are in the top 10 percent of all performers. Given this tendency to rate ourselves very highly, a strength can become dangerous.

“There was this company that had an outstanding strategist,” Hanna said. “His ability to execute under the toughest conditions was unparalleled, but he did not exemplify good business ethics, and ultimately, he lost his job because that placed the company at risk.”

It’s easy to overplay strengths. “The problem with a single-minded focus on strengths is not just that it ignores weaknesses, but that it can actually promote strengths that become weaknesses through overuse,” said Robert Kaiser of Kaiser Leadership, editor of “The Perils of Accentuating the Positive” and co-author of The Versatile Leader,” which contains the Leadership Versatility Index, which has a global database of 14,000 respondents.

The leading cause of derailment is a lack of interpersonal skills, a direct result of too much reliance on what one already knows, as Michelin’s Coyco realized. “I learned that the strengths that made me a success at one time were becoming a source of potential failure if I were to overplay them,” he said.

Overplaying strengths in this way appears to be epidemic, according to LVI data from a 2009 study on 421 upper-level managers from 15 different companies in the U.S., each rated by 10 co-workers on average. Things haven’t changed much since then.

“Over half [55 percent] of upper-level managers were rated as doing too much on at least one of the four broad dimensions of forceful, enabling, strategic and operational leadership,” Kaiser said. “And every single participant was rated as doing too much on at least one of the 48 specific behavioral items. Most managers were rated as doing too much on 10 or more of the 48 items.”

Kaiser also said only 47 percent of those rated as overdoing strengths also rated themselves in the same way. This suggests the majority of managers who overuse their strengths evidently do not recognize their tendency to go overboard. “This may be the worst career-limiting blind spot of them all.”

Organizational Implications
Few behaviors stymie teams and organizations like overplayed strengths, a root cause of defensive routines. Under competitive stress, people retreat to what they know best, and when this is common across the organization, it results in not being responsive to changes in the marketplace.

For example, Hanna said he sees negative financial implications in manufacturing when weaknesses are ignored. Companies that concede they have strategy people and execution people are creating gaps in their value. “If you have five processes end-to-end in the value chain and each process is at 95 percent quality, the customer only gets 75 percent of the product value.”

Hanna said the book “American Icon: Alan Mulally and the Fight to Save Ford Motor Company,” by Bryce Hoffman validates this idea. “Mulally brought in his managers every week and learned what was going on and how they interact,” he said. “Everyone had to play different roles and help each other, while a lot of companies are just doing what they do.”

Sometimes personalities prevent people from completely overcoming their weaknesses. Simply being willing to accept this helps us build better teams. Coyco said he had to realize that he would never transform all of his weaknesses to strengths. “To be successful, I put around me people who I could trust, who trusted me, who were different from me and whose strengths would be complementary to mine.”

Today, Coyco is a professor at HEC Paris, where he shares his experiences with a new generation of leaders. He said one of the key messages he offers them is to be aware of their strengths and recognize that these make them unique. However, they need to recognize and be aware of their weaknesses. “I am insisting all the time: ‘Please don’t ever, ever overplay your strengths just for the sake of accepting your limitations.’ It is your responsibility to work on your weaknesses.”

Learning in a corporate setting is a process of development that needs to push everyone beyond the skills, behaviors and abilities they bring in on day one. A learning organization has a responsibility to offer individuals the opportunity to grow into new roles. It can derive many competitive advantages from a commitment to well-rounded development.

Strengths alone are not enough, and those same strengths actually become weaknesses when overplayed or when there are gaps in organizational strength.

“If you think your strengths will carry the day in general management,” Hanna said, “it’s not going to happen.”

Read the sidebar to this article, “How Avery-Dennison Does Strengths Right.”

Randall P. White is founding partner of Executive Development Group and on the faculties of Duke Corporate Education and HEC School of Management.