Table 1.

Definitions of behavioural proxies used to identify intentional gestural signalling

Term	Definition
Audience checking	the signaller checks the recipient’s state of visual attention before the production of the signal and adjusts her signalling accordingly (e.g., using visual-only signals when the recipient is looking and audible or tactile ones when he is not, increasing the changes of a signal being perceived and showing so-called “sensitivity to the attentional state”)
Response waiting	the signaller pauses and waits for the recipient to respond to his request (behavioural cue here is a pause in gesturing and the visual monitoring of the recipient)
Goal persistence	the signaller continues to signal when the recipient does not respond and either persists and/or elaborates with more gesturing until the goal is met
Mechanical ineffectiveness	the signaller’s gesture may (mechanically) manipulate the recipient but never to an extent that fulfils the goal itself (the gesture action is mechanically ineffective: a ‘push’ may be used to signal to the recipient to move his body in a certain direction, but the force used should not be effective in moving the recipient’s body to the desired location)