This chapter addresses facial expression and its potential for communication, a much-debated issue especially in regard to emotion expression. This expressive potential is thought to co-evolve with facial expression perception and to be critical in social life. Factors affecting the perception of human facial emotion have been explored over the last few decades and they encompass sender and context features, as well as the decoder’s traits. One of the most neglected traits is that of the decoder’s empathy. The co-evolution of emotion signaling, emotion perception, and emotion expression regulation are, according to recent evidence, most certainly linked to empathy, particularly to the extremes of trait empathy—at one end, very poor decoders, and at the other end, higher than average emotion decoders. Studies on nonhuman primate expressive communication, empathy, and prosociality, and clues from the fossil record, may provide insights on the links between emotion expression, empathy and prosociality in human evolution.