There has been much research on the effectiveness of animated pedagogical agents in an educational context, however there is little research about how the emotions they display contribute to a learner's understanding of the lesson. The positivity principle suggests that learners should learn better from instructors with positive emotions compared to those with negative emotions. Additionally, the media equation theory (Reeves and Nass 1996) would suggest this principle should be true for animated instructors as well. In an experiment, students viewed a lesson on binomial probability taught by an animated instructor who was happy (positive/active), content (positive/passive), frustrated (negative/active), or bored (negative/passive). Learners were able to recognize positive from negative emotions, rated the positive instructors as better at facilitating learning, more credible, more human-like, and more engaging. Additionally, learners who saw positive instructors indicated they tried to pay attention to the lesson and enjoyed the lesson more than those who saw negative instructors. However, learners who saw positive instructors did not perform better on a delayed test than those who saw negative instructors. This suggests that learners recognize and react to the emotions of the virtual instructors, but research is needed to determine how the emotions displayed by virtual instructors can promote better learning outcomes.