Inner speech experience varies from constant to absent in adults. Anendophasia names complete lack of inner speech. Low inner speech adults scored lower on verbal working memory tasks. They showed more difficulty on rhyme judgments. Task-switching performance unrelated to inner speech levels. Categorical effects on perceptual judgments unrelated to inner speech. Low inner speech group numbered 46 participants. High inner speech group numbered 47 participants. Four studies tested behavioral consequences of anendophasia.