If you want to change the behavior of someone you work with, simply behave the way you would like them to. For example, if a team member is negative during most of their conversations in the staff room, don’t get sucked into joining the negativity. Simply respond in a positive way. Eventually they will get the message that you’re not interested in office gossip. The best way to help people change is not by challenging them, but by showing them and demonstrating a better pathway.