The cerebral networks important for social behavior include several cortical areas within the temporal and prefrontal lobes, structures like the amygdala and hippocampus, as well as areas involved in motor processing like the premotor cortex, which are linked to the mirror neuron system. However, the fine-grained mechanisms at play within these circuits remain elusive, in large part because we lack tools to investigate brain function in a naturalistic, ethologically valid context in which social interactions could take place. We are currently developing techniques to wirelessly record brain activity in freely-moving monkeys as they perform goal-directed actions and also as they observe the actions of a conspecific or as they interact with them. Our objective is to achieve, through this novel approach bridging neurophysiology and ethology, a new understanding of how information about the social environment is acquired and represented at the neuronal and circuit levels.