When rhesus monkeys are separated from their mothers, one of their most common responses is to cry. When they are lost or separated from their caretakers, dogs shed tears. Even rat pups emit something that sounds like crying when they are suddenly isolated. The seemingly obvious conclusion: animals cry. A recent report comes from a certain baby elephant whose tears made global headlines (as cute creatures tend to do): he was crying over being separated from his mother.
If you look at the photographic evidence, he certainly seems to be—as do many other elephants before him, whether it's because they've been abandoned or simply hurt. And the people who have witnessed these tears—from elephants and other creatures of the wild alike—are adamant that the watery eyes they see in the beasts' eyes are signs of genuine, emotional manifestations.
As documentary filmmaker James Honeyborne, who has for over twenty years filmed animals in the wilderness, puts it, "I am certain that the behavior I have witnessed so often stems from real emotion."
Does that certainty, however, have a scientific foundation?
Honeyborne isn't the first to make the leap from visible tears to human-like emotion. In the 1899 Expression of Emotions in Man and Animals, Charles Darwin included an entire chapter devoted to suffering and weeping—and cited evidence of one particular animal, the Indian elephant, as weeping in human-like fashion when placed in situations of distress or despair. Darwin's evidence, however, was anecdotal. He couldn't be sure whether he was seeing genuine feeling or a physiological necessity caused by trauma. While we can ask a human to describe an internal state—an answer to the simple are you feeling sad? should suffice—it's far more difficult to make the connection between outward appearance and inner emotion in a non-human animal.
In recent years, scientists have been attacking the problem from a different angle: true, we can't ask an elephant directly if he's got the blues, but we can look at his behavior and his brain to see if we can't spot the same correlates that we see in sad humans. One promising approach is to look for the cognitive biases that we know tend to occur more frequently in negative emotional states. For instance, when we're anxious, we tend to become more pessimistic, viewing neutral-seeming things, such as a chair, as more negative, expressing greater fear of punishment, and becoming more generally avoidant in our behavior. We can use these tendencies to predict how an animal in different emotional states will react to different neutral or ambiguous events: will he interpret them as positive or negative, approach or avoid them, show fear or not? Thus far, this approach has proven quite productive—and researchers have found behavioral evidence of affective bias in animals ranging from honeybees, tosheep, todogs and certain types of monkeys. In that sense, at least, animals do predictably experience some degree of lasting emotion—and perhaps even an emotion that would lead to tears of distress.
Additional evidence of animal emotionality comes from neuroscience: do the brains of animals react in similar ways to the brains of humans who are experiencing certain emotional states? In other words, if we were to look at that baby elephant's brain as he cries, would we see the same sorts of activity that we would in a crying infant who was likewise separated from his mother? While elephants, alas, are a bit too large for the scanner, other candidates, including chimpanzees,monkeys, dogs, androdents, abound—and thus far, the evidencehas been promising. Animal brains seem to react in homologous fashion to human in emotions that range from fear, to anger, to joy and emotional attachment. And they even respond in similar fashion to displays of emotion in others, the type of empathy that many researchers once believed to be unique to humans. In one recent study from primate researchers in Japan, scientists measured event-related brain potentials (ERPs) in awake chimpanzees as they looked at pictures of either emotional or neutral faces. The chimpanzees, as it turns out, exhibited the same brain pattern as their human counterparts when looking at the emotional pictures, suggesting that, even if they can't vocalize what they are feeling, the underlying process may be similar to what we term traditional emotion.
So where does that leave us: when animals cry, are they crying, in the full human sense? The jury is still out.
We tend to associate certain human facial expressions with corresponding internal states: someone who cries is sad; someone who laughs is happy; someone who furrows his brow is stressed or anxious. But we have little way of knowing if the same analogues hold in the animal world, or if we're just reading into a physical response that we recognize from our own behavior. An elephant's tears may be expressing real sadness—or they could be just a physiological stress response, be it to separation from a mother or the related absence of touch. At the end, though, does that distinction really matter? Even in humans, tears can means myriad things—from sadness, to frustration, to anger, to those moments when you're not even sure why you're crying to begin with. And human or other animal, no matter if the tears are instinctual or conscious, once shed they attain the same purpose—the purpose of most any bout of crying, whatever the reason: to be comforted, whether it's by a fellow elephant or a sympathetic human.