Draw attention to inappropriate behavior
If you notice a particular case of inappropriate behavior, do not ignore it. Ask, for example: "I noticed that you did not say anything about your colleague's presentation, you only rolled your eyes. What happened?" Always ask an open question so that the employee can express their opinion. Use the answers to search for the causes of the animosity.
Try to uncover real feelings
The most common causes of strong emotions, including animosity, include low self-esteem, fear of change or loss of control. Talk with both employees and ask what they are afraid of, and how they feel when they are treated badly by their colleague. Your goal is to help both of them understand how their own feelings and thoughts influence their perceptions of others.
Help both the parties understand each other
Ask the two employees to assume that the other is trying to handle the situation in the best possible way he knows how. Again, asking questions will help you. Ask e.g.: "How do you think the other person feels and how you can help him so that your relationship could improve?"
Arrange a dialog
Invite both employees in and explain it is high time for them to talk. Let them talk without interrupting. Enter the discussion only when you see something substantial that they have not spoken about yet, e.g., "We talked about how you feel when your colleague ignores your presentations ..."
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