A mirror neuron is a neuron which fires both when an animal acts and when the animal observes the same action performed by another (especially conspecific) animal.[1] Thus, the neuron “mirrors” the behavior of another animal, as though the observer were itself acting. These neurons have been directly observed in primates, and are believed to exist in humans and other species including birds. In humans, brain activity consistent with mirror neurons has been found in the premotor cortex and the inferior parietal cortex.

http://en.wikipedia.org/wiki/Mirror_neuron

see also Theory of Mind in Robotics