seems to be a good article on a good site : Don't criticize, condemn or complain.

among other nice points in the article, there is the following quote :

"In the field of management, there is the intriguing work of Daniel Isenberg, a Harvard Business School professor who has spent many years studying the qualities which differentiate a dynamic executive from his less successful contemporaries. Contrary to the popular stereotype of the high achiever as an arrogant autocrat, impatiently judging colleagues and insensitive to the needs of subordinates, Isenberg has found the most successful senior managers are quite extraordinary in their ability to refrain from overt criticism of others, often humorously conceding when they themselves are wrong. They also take a greater than normal interest in the emotional comfort of their fellow workers and have a tendency to transform everyday resentments over unexpected problems into constructive questions about how to improve their company’s operations."