In Oren Rudavsky's recent film, The Treatment, a wealthy Manhattan widow is baffled that a schoolteacher might be so anxious about speaking in public that he can't eat and suffers from stomach cramps and diarrhea. After all, surely he must speak in front of others every day. His reply is, in effect -- well, yes, but only in front of students. The schoolteacher probably wouldn't take any comfort from the popularity of his fear: According to one notorious statistic, Americans are more afraid of public speaking than of death.
I've begun with this example it points up a real enigma about our minds: How can a purely cultural experience such as public speaking translate into brain chemistry? After all, neither term in "public speaking" is straightforward. How big a group counts as "public"? Are they friends, colleagues, strangers, or a mix? Am I drunk or sober? Am I reading a prepared speech? fielding questions? participating in a judicial, civic, or religious ritual? How is it that our serotonin levels are able to make such finegrained judgments? Even if one focuses just on physical responses -- mild sweat, an elevated heart rate -- people may well attribute different meanings to those responses. (I was scared / I was in the zone / I was angry.) Despite these difficulties, some psychiatrists have proposed that "public speaking phobia" ought to receive its own diagnostic classification.