I recently posted a review of Thomas Bullard’s book, The Myth and Mystery of UFOs. In that review I noted that Bullard favors the psycho-social interpretation of UFOs. There was some discussion in the comments about Jerome Clark, the famous UFO researcher, who had been an adherent of the psycho-social view but then abandoned it. I photocopied Clark’s article on the psycho-social interpretation from the 2nd edition of his two-volume UFO Encyclopedia and scanned if for those interested. Like everything else in that encyclopedia, an excellent article.