Word Frequency Effect

James McKeen Cattell made the first systematic observation in 1886 at Wilhelm Wundt's Leipzig laboratory, using a tachistoscope to show that familiar words were recognised faster than rare ones. The effect was formalised and named by Davis H. Howes and Richard L. Solomon in two 1951 papers at Harvard, establishing that recognition thresholds decrease logarithmically with word frequency. The finding has since become one of the most replicated results in psycholinguistics, with implications for reading instruction and language processing models.