To what extent does a manager's 'knowledge' in human behavior affect employee performance?

To a great extent,in due course you may become a Manager,you can use the knowledge your previous Manager has given you,it;s an endless process.

Knowledge of human behavior at managerial level plays a vital role in employees performance, if managers know the human behavior in a particular situation there decision, actions and policies will be designed and altered in such way which is accepted at all level of employees and have the minimum resistant to change.