On the relationship between leadership styles and performance, using NBA coaches and NBA players as the data set:
Specifically, experiencing abusive leadership at any point across the 6 years of the study shifted the trajectory of player performance downward. By moving beyond static relationships and demonstrating career-long performance effects, this finding extends inferences about abusive leadership from prior research. Giving added importance to this finding, the task performance measure was derived from objective performance data (rather than supervisor ratings that typify prior research), and the measure of task performance (i.e., player efficiency) is routinely used within the industry for major personnel decisions (e.g., hiring, salary, renewal).
Here is the paper.
This feels like a giant warning sign to me: look at how much impact positive management can make. Look at how much abusive management costs. If coaching style matters this much for NBA players, how much more important is parenting style?