To change his behavior, I suggest proceeding with the following steps. First, let him know his "mansplaining" is having a deleterious effect. Try approaching him with a statement along the lines of "Don, you may not realize this, but you seem to feel the need to explain things to the female members of the team who don't need an explanation. You are talking down to them, and it needs to stop immediately."

Second, put him in charge of reversing his own behavior. You might suggest some tactics to help him eliminate this pattern with female co-workers, such as pausing before delivering unsolicited information and focusing on asking more questions and making fewer statements. Last, schedule follow-up meetings over the next few weeks to check his progress. Before you meet, ask female team members if they have noticed an improvement in his conduct, as that knowledge will help you steer the supplementary sit-downs in an appropriate direction. Over time, you should be able to create an atmosphere where "Mad Men" behavior is only on TV, not in your office. E