The simple act of noticing someone's eye color can build your empathy, explains Alan Alda, who got so curious about empathy one day that he began to experiment on himself. Any time he'd interact with someone, he would try to figure out what they were feeling, and name their emotional state (using strictly his inside voice). This exercise inspired psychologist Dr. Matthew Lerner to conduct a scientific study on empathy, and how it can be bolstered by practicing visual perception. Alda lists the benefits of paying more attention to the people you encounter each day as numerous: annoying people become easier to tolerate, discussions become more productive, you feel more relaxed, which is contagious to those around you—you can even become a better conversationalist and writer. He is full of praise for the effect of empathy on communication, but not without caveat: he warns that empathy must be managed and edited in order to be a successful tool, otherwise it can work against you. Alda has summarized his adventures in the art and science of communication in his book If I Understood You, Would I Have This Look on My Face?