Presented as part of the ANU Linguistics Seminar Series

True synonyms are very rare across the world's languages, but homonyms/homophones are ubiquitous. This represents a problem for recent evolutionary accounts of language change, which tend to assume most change is either neutral/drift-like or involves some form of selection. This suggests that homonyms are either unaffected by neutral change, or are somehow positively selected for. This is the opposite of what one might expect: although synonyms are redundant and increase the burden on the learner, homonyms introduce systematic ambiguity and work against communicative function.

Experimental work by Vanessa Ferdinand (Santa Fe Institute) on the evolution of linguistic regularization has identified a specifically linguistic and communicative bias which acts to reduce variation in the lexicon over time. We have extended this work to include homonyms: our results suggest that while learners are highly sensitive to input frequencies, speaker performance involves reducing uncertainty for hearers, whether this acts on word or object associations. This suggests that homonyms are so frequent because they somehow manage to avoid this effect, probably via disambiguation in context.