Paired-associate lists were constructed so that 4 words were paired with the same nonsense syllable response. The differences in learning the lists were not related to the ratings of association between the stimuli. Found that differential difficulty was due to differential intragroup transfer between stimuli. Concluded that the difficulty in learning the lists was related to the difficulty in learning a mediating response for each group of stimuli, and this was not predictable from association ratings. (PsycINFO Database Record (c) 2006 APA, all rights reserved)