Behavioral experiments

Phonology offers a unique case for the debate on cognitive vs. cultural factors that avoids the duplication problem: unnatural alternations. Based on a large typological study, we establish the Minimal Sound Change Requirement (MSCR) stating that unnatural alternations can arise only through a combination of minimally three sound changes and provide a formal proof for MSCR. Crucially, even if cognitive and historical influences are conflated for frequency and directionality of each individual sound change, it is only Cognitive Bias that influences probability of a combination of individual sound changes that produces the unnatural alternation. By bootstrapping the probability of a combination of three sound changes that yield an unnatural alternation (e.g. post-nasal devoicing), we estimate the historical contribution to typology and compare it to results from artificial grammar learning experiments.