Does gesture follow speech in describing metaphorical motion events over developmental time?

Children learning structurally different languages display variability in the way they package semantic elements of a physical motion event in gesture, mirroring the patterns found in speech for the same events. In this study, we ask whether these differences extend to metaphorical motion events and, if so, when in development the patterns become evident. We studied the speech and gestures produced by 100 children learning English or Turkish (n = 50/language)-equally divided into 5 age groups: 3-4, 5-6, 7-8, 9-10, 11-12 years-when describing metaphorical motion events (e.g., idea runs out of the mind). We compared the patterns to previously reported findings on the same children describing physical motion (e.g., girl runs out of the house). Our results showed evidence for cross-linguistic differences in the expression of metaphorical motion events in both speech and gesture, akin to cross-linguistic differences observed in the expression of physical motion events. But language-specific patterns emerged later in metaphorical than in physical motion descriptions, both in speech and in co-speech gesture. Our results suggest that gesture and speech form tightly integrated systems in the expression of metaphorical concepts, as they do for the expression of physical events, by children learning structurally different languages.