Jean-Gabriel De Tarde or Gabriel Tarde in short (March 12, 1843 in Sarlat, France – May 13, 1904 in Paris) French sociologist, criminologist and social psychologist who conceived sociology as based on small psychological interactions among individuals (much as if it were chemistry), the fundamental forces being imitation and innovation.
Among the concepts that Tarde initiated were the "group mind" (taken up and developed by Gustave Le Bon, and sometimes advanced to explain so-called herd behaviour or crowd psychology), and economic psychology, where he anticipated a number of modern developments. However, Emile Durkheim's sociology overshadowed Tarde's insights, and it wasn't until US scholars, such as the Chicago school, took up his theories that they became famous.
Tarde's interest in criminology arouse while he was working as a magistrate in public service. Tarde was interested in the psychological basis of criminal behavior. He was critical of the concept of the atavistic criminal as developed by Cesare Lombroso. Tarde's criminological studies served as the underpinning of his later sociology .
Interestingly Tarde also produced one science-fiction novel entitled Underground Man. This novel tells the tale of a post-apocalyptic earth covered by ice where the surviving humans has gone to live underground. The novel develops on the new culture which is created by the humans where music and art are the dominating aspects of lives.