Classically, the question of recognizing another subject is posed unilaterally, in terms of the observed behaviour of the other entity. Here, we propose an alternative, based on the emergent patterns of activity resulting from the interaction of both partners. We employ a minimalist device which forces the subjects to externalize their perceptual activity as trajectories which can be observed and recorded; the results show that subjects do identify the situation of perceptual crossing with their partner. The interpretation of the results is guided by comparable evolutionary robotics simulations. There are two components to subjects’ recognition capacities: distinguishing mobile and fixed entities; and behaving so as to interact with their partner rather than with a mobile lure. The “Other” is characterized by the feature that there is sufficient regularity in the interactions to encourage the formation of anticipations; but sufficient indetermination that the actual behaviour is consistently surprising.