Darwinian Evolution of Culture as Reflected in Patent Records

We argue that culture undergoes an evolutionary process, analogous to biological evolution. As evidence, we analyze the bibliographic information of all utility patents issued in the United States from 1976 through 2007, which comprise over three million patents. The set of issued patents is regarded as an evolving population. A patent is considered to “reproduce” when it is cited by a new patent, and variability is introduced into the population by the innovations in new patents. We analyze patent records with statistics that quantify the degree to which the population of patents is shaped by natural selection, and we find convincing evidence of Darwinian evolution. Further, weighting our statistics by the classification distance between parent and child shows that the most fecund patents are “door-opening” technologies that enable an especially broad range of further innovations.