Pesek lecture: SETI and society – Decision trees

This paper presents a simplified decision tree diagram for SETI (the Search for Extraterrestrial Intelligence) and society. It deals with the series of steps and circumstances that follow from the quest for evidence of the existence of extraterrestrial civilizations, with the major goal of including those branch points which involve decisions that are societal rather than scientific or technological. Since SETI is based on science and technology these factors are also included in the decision diagram, but more in a summary fashion. A condensed list of the relevant societal disciplines is given. The most difficult decisions are those related to issues of transmitting communications from Earth to ETI. The diagram may be useful as a new way of looking at the subject of Communication with Extraterrestrial Intelligence (CETI), and how it inevitably blends into SETI. Arguments are made for vigorous pursuit of studies in all the societal cultural and behavioral domains involved, and it is shown that many of these studies can profitably be undertaken now, before an ETI signal has been detected. Not least, it is argued that the newly emerging field of CETI and Society would benefit materially from the application of formal decision theory and analysis, and from game theory and utility theory.