Implicit Knowledge of Word Stress and Derivational Morphology Guides Skilled Readers’ Decoding of Multisyllabic Words

In oral language, morphologically conditioned regularities around stress assignment can be found in two classes of derivational suffixes, one that causes lexical stress to shift to the syllable immediately preceding the suffix (ACtive – acTIVity) and one that has no effect on stress (SILLy – SILLiness). In this study, adults listening to spoken “derived” nonwords judged as preferable those wherein the stress placement was consistent with morphological regularities of English. When reading nonwords and a set of nonwords derived from them, readers reliably assigned stress to the syllable predicted by the morphology. This effect was significantly associated with scores on standardized measures of word reading after controlling for nonword reading ability, showing that the relationship was not merely an artifact of decoding skill. These findings support the importance of the interface between morphology and suprasegmental phonology as a key factor in the way English-speaking readers approach multisyllabic, morphologically complex words.