This paper tests the hypothesis that the iconicity inherent in human gestures can be a key element in the creation and evolution of communication systems. An interactive experiment based on playing charades was conducted modelling a situation where a multimodal (gesture + sound) and semiotically mixed (non‐arbitrary + arbitrary) communication system evolves through social collaboration. The experimental design was based on Garrod and colleagues’ (2007) modelling of iconic graphical signals’ transformation into symbolic ones through interactive communication experiments. The reported experiment, however, diversified from the original in certain ways; (a) graphical representations were replaced by gestural representations (i.e. pantomime); (b) a vocalization component became mandatory in one of the experimental conditions; and (c) feedback exchange between participants was not allowed. Comparing the evolution of gestural communication across two separate conditions (‘Gesture‐only’, ‘Gesture‐and‐sound’), the experiment reveals that in the absence of feedback, simplification (i.e. reduction of forms) and refinement of signs is still attainable; albeit with significant differences across the two conditions. It is possible that pantomimic gestures can serve as a bootstrapping device between meanings and arbitrary sounds – even in the absence of feedback – if the latter are repeatedly associated with iconic gestural signs in the context of reciprocal pair‐wise interactions. Although gestures in the experiment lose some of their initial iconic features due to their simplification and refinement, it cannot be argued that they have transformed into symbols – gestures can remain iconic and at the same time be shared between people who have never interacted before.