Commentary: Evolution and Nonverbal Behavior: Functions and Mediating Processes

The articles in this special issue provide important, new insight into the evolutionary roots of expressive behavior. Across the three articles, a strong argument is made for behavioral mimicry, expressivity, and laughter providing adaptive value to ancestral humans that is still reflected in our modern world. The place of an evolutionary analysis in the development of a broader functional approach to nonverbal communication is described and discussed. Each article proposes specific dynamics through which expressive behaviors predispose receivers to respond in a manner benefitting the sender. The mediating mechanisms advanced in the articles are examined more closely and modifications in the proposed processes are considered.