Fig. 3.

The social signalling framework in the context of imitation. In a typical imitation sequence (a), one person acts, the second copies, and the first responds to being imitated; this is represented as a pseudo-conversation, where red bubbles are the woman’s action/cognition and blue bubbles are the man’s action/cognition. Two predictions must be true to classify imitation as a signal. First, the imitator (sender) produces the action more when he can be seen (b); data in Panel b confirms this (Krishnan-Barman & Hamilton, 2019). Second, the imitatee (receiver) must detect on some level that she is being copied and must respond (c); brain systems linked to this process are summarised in Panel c (IPL = inferior parietal lobule; TPJ = temporo-parietal junction; IFG = inferior frontal gyrus; vmPFC = ventromedial prefrontal cortex; Hale & Hamilton, 2016a). (Colour figure online)