The Development of Rhythmic Categories as Revealed Through an Iterative Production Task

Both humans and some non-human animals (e.g., birds and primates) demonstrate bias toward simple integer ratios in auditory rhythms. In humans, biases are found for small integer-ratio rhythms in general. In addition, there are biases for the specific small integer-ratio rhythms common to one’s cultural listening experience. To better understand the developmental trajectory of these biases, we estimated children’s rhythm priors across the entire human rhythm production space of simple rhythms. North American children aged 6-11 years completed an iterative rhythm production task, in which they tapped in synchrony with repeating three-interval rhythms. For each rhythm, the child’s produced rhythm was presented back to them as the stimulus, and over the course of 5 iterations we used their final reproductions to estimate their rhythmic biases or priors. Results suggest that children’s rhythmic priors are (nearly) integer ratios, and the relative weights of the categories observed in children are highly correlated with those of adults. However, we also observed age-related changes especially for the ratio types that vary most across cultures. In an additional rhythm perception task, children were better at detecting rhythmic disruptions to a culturally familiar rhythm (in 4/4 meter with 2:1:1 ratio pattern) than to a culturally unfamiliar rhythm (7/8 meter with 3:2:2 ratios), and performance in this task was correlated with tapping variability in the iterative task. Taken together, our findings provide evidence that children as young as 6 years old exhibit categorical rhythm priors in their rhythm production that closely resemble those of adults in the same culture.