Coprolalia is a condition that affects about 15 % of people with Tourette syndrome . A more recent Brazilian study of 44 patients with Tourette syndrome found a 14 % rate of coprolalia ; a Costa Rican study of 85 subjects found 20 % had coprolalia ; a Chilean study of 70 patients found an 8.5 % rate of coprolalia ; older studies in Japan reported a 4 % incidence of coprolalia ; and a still older clinical study in Brazil found 28 % of 32 patients had coprolalia . Considering the methodological issues affecting all of these reports , the consensus of the Tourette Syndrome Association is that the actual number is below 15 percent .