Provide students with a definition of the term "empathy." Tell them that empathy is the ability to identify and share the feelings of others. Provide them with an example of empathy, such as crying when you notice that someone is sad.
Show students images of faces expressing different emotions, positive and negative. Look for pictures in magazines; faces from war-torn countries are likely to express sadness, while faces in comedy audiences are likely to express positive emotions. Cut these kinds of images out of magazines and distribute them to your students.
Ask your students to identify the emotions expressed in the images you distributed. Do not make the mistake of thinking there is one correct answer: "content" and "happy" can easily apply to the same picture. Do, however, take note if a student gives an obviously wrong answer, like "elated" for a frowning face.
Ask your students to give examples of times they felt strong emotions. Go around the class, and give each student an opportunity to volunteer an answer. Ask students to describe times they felt strong emotions as well as negative emotions. Ask them what caused them to feel these emotions so strongly at the time they felt them.
Give your students a writing exercise in which they have to imagine situations that might have generated the emotions in the magazine cutouts. Ask them to write two to three paragraphs on this topic; a full essay is a bit much to ask of a middle school student. If students have a hard time imagining situations that lead to strong emotions, ask them to try to recall the situations that made them feel strong emotions in the past.