Speakers’ gestures predict the meaning and perception of iconicity in signs

Sign languages stand out in that there is high prevalence of conventionalised linguistic forms that map directly to their referent (i.e., iconic). Hearing adults show low performance when asked to guess the meaning of iconic signs suggesting that their iconic features are largely inaccessible to them. However, it has not been investigated whether speakers’ gestures, which also share the property of iconicity, may assist non-signers in guessing the meaning of signs. Results from a pantomime generation task (Study 1) show that speakers’ gestures exhibit a high degree of systematicity, and share different degrees of form overlap with signs (full, partial, and no overlap). Study 2 shows that signs with full and partial overlap are more accurately guessed and are assigned higher iconicity ratings than signs with no overlap. Deaf and hearing adults converge in their iconic depictions for some concepts due to the shared conceptual knowledge and manual-visual modality