Assessing the psychological status of the vowel shift rule

Several experiments designed to test the psychological validity of Chomsky and Halle's (1968) Vowel Shift Rule are reviewed, and both positive and negative evidence is evaluated. Moskowitz's (1973) claim that speakers' knowledge of vowel alternations is due to their knowledge of spelling rules is introduced, and an experiment designed to differentiate between behavior based on the Vowel Shift Rule and on spelling rules is presented in detail. It is shown that subjects in this experiment, and in previous experiments that claimed to have obtained positive evidence for the Vowel Shift Rule, are behaving in accord with spelling rules and not the Vowel Shift Rule. It is argued that literacy is a possible source of psychologically real linguistic knowledge.