The "Jumping Frenchmen of Maine" were described by George Beard in 1878. They had an excessive startle response, sometimes with echolalia, echopraxia, or forced obedience. In 1885, Gilles de la Tourette concluded that "jumping" was similar to the syndrome that now bears his name. Direct observations of jumpers have been scarce. We studied eight jumpers from the Because region of Quebec. In our opinion, this phenomenon is not a neurologic disease, but can be explained in psychological terms as operant conditioned behavior. Our cases were related to specific conditions in lumber camps in the 19th and the beginning of the 20th century.