Research scientists at the Max Planck Institute for Biological Cybernetics have confirmed, using MRI imaging, that animals are particularly adapt at reading faces of their own species. Even humans and macaque monkeys, although similar in appearance (no offense to either species), have trouble focusing on the others’ faces.
From the Max Planck Society:
In the study, faces of the two species were shown to both monkey and human observers while their eye movements were being recorded. The faces were presented both "normally" and upside-down. It is a well-known effect in perceptual psychology that upside-down faces are hard to recognize as the usual face processing mechanisms cease to work. In addition, we know that gaze is attracted to the eyes for "normally" shown faces. These two facts can therefore be used to uncover different processing strategies: many fixations on an eye region are a tell-tale sign of "normal" face processing.
The study has shown that this processing strategy in monkeys only holds for monkey faces, whereas in humans it only holds for human faces – even though the two species share rather similar facial features (eyes, nose, mouth). In addition, the recorded eye movements of both species were exactly the same for non-conspecific faces as for upside-down faces: in both cases fixations moved away from the eyes to other parts of the face.
Monkeys are therefore experts for monkey faces and humans experts for human faces. "The surprising finding is that in addition the perceptual strategies for processing conspecific faces are exactly the same. Humans and monkeys are therefore even more similar than previously thought," said Christoph Dahl, one of the two main authors of the study.