"Do you want a 'real' experience to talk about when you get home from your vacation? Come and get yourself Activationized!"
This intriguing invitation, LIFE magazine informed its no-doubt head-scratching readers in August 1948, had been distributed on posters and flyers around Cape Cod's Provincetown that summer in order to entice potential devotees and to signal the birth of what LIFE (tongue-in-cheekily) classified as a brand-new American "cult": Activationism.
Activationism's founder and driving creative force, Milton Hood Ward, "counseled his followers, which included housewives, waitresses, fishermen and would-be artists, to uncork their emotions all over the place. 'Activate or Deteriorate' was his motto.
"A composer and press agent,," LIFE went on, "Ward [had witnessed] Indian and Haitian dancers whooping up their tribal rites, and figured that inhibited Americans would feel better if they did the same thing. ... Although Activationist practices varied widely, they generally started with group calisthenics and chanting and went on through progressive frenzies to extemporaneous dancing and ad lib yelling.
"At Provincetown," the 1948 LIFE article concluded, "where crazy summertime goings-on are [quite common], not many Activationists took their cult seriously. Ward, however, thinks he may have started something, and plans to introduce Activationism to New York this fall in an art gallery, a nightclub, and Carnegie Hall."
Alas, there are no records indicating that Activationism survived past that one magical New England summer. All these years later, in an age of seemingly ceaseless anxiety and sky-high levels of stress, Americans (and most everyone else on the planet) could probably benefit from the emergence of another harmless, playful, free-spirited new "cult." Is it too much to hope that, someday, a handful of creative souls might reawaken the Activationist spirit that briefly flowered, long ago, on the beaches of Cape Cod?
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.