As filmmakers, we're constantly always looking for something to bring the audience deeper into the reality of the story we're telling.
Man is said to be a reasoning animal. I do not know why he has not been defined as an affective or feeling animal. Perhaps that which differentiates him from other animals is feeling rather than reason. More often I have seen a cat reason than laugh or weep. Perhaps it weeps or laughs inwardly - but then perhaps, also inwardly, the crab resolves equations of the second degree.