New neighbours make bad fences: Form-based semantic shifts in word learning

The meanings of words sometimes shift towards those of similar-sounding words. For example, expunge is etymologically related to puncture but now connotes "wiping away," and according to the Oxford English Dictionary, this shift "is probably influenced by phonetic association with sponge." However, evidence for such form-based semantic shifts is anecdotal. We therefore conducted two experiments where participants learned novel words in sentence contexts (e.g., The boss embraiched the team's proposal, so they had to start over) and applied the inferred meanings to ambiguous sentences by providing ratings on a 7-point scale (e.g., Carol embraiched Gerald. How pleased was Gerald?). The inferred meanings of novel words that are spelt like existing words (e.g., embraich, like embrace) shifted towards the meanings of those existing words, relative to control novel words learned in identical contexts (e.g., fline; participants rated Gerald as more pleased to be embraiched than to be flined). These experiments provide the first evidence that newly learned words can indeed undergo form-based semantic shifts. We propose that shifts like these occur during word learning, when words activate rather than inhibit similar-sounding words, and we discuss why they seem to be more common in low-frequency words.