One of my coauthors described his participation in a psychology experiment where he was supposed to navigate a maze of some kind. But, as with most psychology experiments, the question wasn't whether he would make it through the maze, but something else. Namely, the experimenter wanted to see how many times, as well as, presumably, when, and where, the research subject said "um" and "ah" when tracing through the maze. The only problem was that my coauthor was very slow and deliberate in his tracing, so he never said "um" or "ah" and had to be ruled out from the dataset as an "outlier." It occurs to me that "um" and "ah" ("filler" words in linguistics terms) might be usable examples of phatics, a bit similar to the example of applause that we talked about recently. I suspect that - outliers like my colleague notwithstanding - some interesting psycholinguistics work has been done to describe the func...