Category competition as a driver of category contrast

Some mental categories map to percepts which are products of human behaviors, such as linguistic signals. Because behavior is learned and updated by experience, biases in the way a behavior is perceived can influence how it is reproduced, allowing behaviorally based categories to evolve over time. Here we show that this perception–production feedback loop can itself promote preservation of contrast between categories. Using both simulation and analytical tools, we show that asymmetries in the mapping of perceptual variants to competing categories acts to sharpen category boundaries. Evidence from patterns of change in modern languages is consistent with this mechanism. Because the ability to maintain a large number of distinct signal/meaning categories is a prerequisite for complex language, this cognitively general mechanism may have contributed to the initial evolution of the language faculty.