This study provided a comprehensive examination of the full range of transformational, transactional, and
laissez-faire leadership. Results (based on 626 correlations from 87 sources) revealed an overall validity
of .44 for transformational leadership, and this validity generalized over longitudinal and multisource
designs. Contingent reward (.39) and laissez-faire (
.37) leadership had the next highest overall
relations; management by exception (active and passive) was inconsistently related to the criteria.
Surprisingly, there were several criteria for which contingent reward leadership had stronger relations
than did transformational leadership. Furthermore, transformational leadership was strongly correlated
with contingent reward (.80) and laissez-faire (
.65) leadership. Transformational and contingent reward
leadership generally predicted criteria controlling for the other leadership dimensions, although transformational
leadership failed to predict leader job performance.