Abstract Astrobiologists are moving purposefully towards the detection of extraterrestrial intelligence (ETI) through the radio and optical methods of SETI. Meanwhile, members of the public have formed their own opinions, only partially informed by science. In the United States, two thirds of all adults believe there is intelligent life beyond Earth, and a substantial minority believe we have already made contact. Opinions about the existence and nature of aliens are part of a complex landscape of beliefs that includes pseudoscience and superstition and extends to conspiracy theories. The widespread belief that unidentified flying objects (UFOs) represent visits by ETI is at the center of this landscape. Beliefs about ETI are also shaped by films, TV shows, and popular culture. This chapter summarizes what the public believes about ETI and presents possible explanations for these beliefs. Some international comparisons are presented. The author has surveyed the opinions and beliefs of tens of thousands of students on topics relating to life beyond Earth and the data gives insights into the modes of thinking of the college-age population. People are not “blank canvasses” when it comes to their beliefs and expectations about ETI, and this should be considered by the scientists who are preparing for eventual, actual contact.
C. Impey (2024) studied this question.