How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified items to a partner using repeated non-linguistic vocalization, repeated gesture, or repeated non-linguistic vocalization plus gesture (but without using their existing language system). Gesture proved more effective (measured (...) by communication success) and more efficient (measured by the time taken to communicate) than non-linguistic vocalization across a range of item categories (emotion, object, and action). Combining gesture and vocalization did not improve performance beyond gesture alone. We experimentally demonstrate that gesture is a more effective means of bootstrapping a human communication system. We argue that gesture outperforms non-linguistic vocalization because it lends itself more naturally to the production of motivated signs. (shrink)

In this paper the cognitive, cultural, and linguistic bases for a pattern of conventionalization of two types of iconic handshapes are described. Work on sign languages has shown that handling handshapes and object handshapes express an agentive/non-agentive semantic distinction in many sign languages. H-HSs are used in agentive event descriptions and O-HSs are used in non-agentive event descriptions. In this work, American Sign Language and Italian Sign Language productions are compared as well as the corresponding groups of gesturers in each (...) country using “silent gesture.” While the gesture groups, in general, did not employ an H-HS/O-HS distinction, all participants used iconic handshapes more often in agentive than in no-agent event descriptions; moreover, none of the subjects produced an opposite pattern than the expected one . These effects are argued to be grounded in cognition. In addition, some individual gesturers were observed to produce the H-HS/O-HS opposition for agentive and non-agentive event descriptions—that is, more Italian than American adult gesturers. This effect is argued to be grounded in culture. Finally, the agentive/non-agentive handshape opposition is confirmed for signers of ASL and LIS, but previously unreported cross-linguistic differences were also found across both adult and child sign groups. It is, therefore, concluded that cognitive, cultural, and linguistic factors contribute to the conventionalization of this distinction of handshape type. (shrink)