Overall leadership ability can in general be improved more effectively by working on a leader’s strengths rather than weaknesses, and leadership strengths can be improved by a form of “cross-training” using complementary strengths, according to John Zenger, Joseph Folkman, Robert Sherwin and Barbara Steel in their book How to Be Exceptional: Drive Leadership Success by Magnifying Your Strengths.
The book begins by explaining the authors’ research findings which demonstrate relationships between leadership effectiveness and employee satisfaction and engagement, and between leadership effectiveness and customer satisfaction. The authors then go on to explain that the strongest leaders possess three or more significant strengths, even if they also have some weaknesses. Provided that the weaknesses are not fatal flaws, it is the leader’s strengths and not his or her weaknesses that define the leader’s leadership effectiveness.
The authors recommend that a leader start by undergoing a 360-degree assessment to measure leadership strengths and weaknesses, as this is more reliable that self-assessment. If the assessment identifies “fatal flaws”, being scores in the bottom 10 percent for important characteristics, the leader should start by working on those flaws; otherwise, the leader should work on enhancing his or her strengths with the aim of becoming exceptional.
In general I found the authors’ arguments persuasive. The book does not provide a description of their research methodology, the charts demonstrating their findings are suspiciously linear, and it does seem doubtful that subjectively perceived leadership characteristics can be measured with precision; but on the whole there does appear to be sufficient evidence to demonstrate that leadership characteristics can be improved, strengths should get more attention than weaknesses, and strengths can be improved by working on complementary characteristics.