Apes do cry out vocally when they’re distressed, but they don’t shed emotional tears. Producing tears in response to sadness, grief, or pain appears to be unique to humans among all known species. Chimpanzees, gorillas, and other great apes scream, whimper, and wail when upset, and they show clear signs of grief and mourning, but their eyes stay dry throughout.
What “Crying” Means for Apes
Chimpanzee infants produce three distinct types of distress vocalizations that escalate in intensity: a mild “hoo” sound, a moderate whimper, and a severe cry that is noticeably louder and more piercing. None of these are accompanied by tears. Adult chimpanzees scream and whimper too. Screams are loud, high-pitched shrieks that can become raspy or hoarse at their most intense. Whimpering sounds like modulated, high-pitched “hoo” sounds and often progresses into full screaming. These vocalizations occur during fear, distress, agitation, or submission, and whimpering is especially common in infants during weaning.
These sounds are paired with dramatic facial expressions. A distressed chimpanzee will open its mouth wide, pull back the corners of its lips, and retract them to expose both upper and lower teeth and gums. To a human observer, the combination of piercing screams and a contorted face looks a lot like crying. But the tear glands stay inactive. Apes produce tears only for the same reason other mammals do: to lubricate and protect the eye.
Why Only Humans Shed Emotional Tears
Emotional tearing likely evolved from the same distress calls that apes still use today. The connection may have started in human newborns, where the intense muscle contractions around the eyes during screaming stimulated sensitive nerves on the cornea, which in turn triggered the tear glands. This is similar to how your eyes water when you yawn: physical pressure near the eye activates tear production as a reflex.
Over time, tears became a signal in their own right. One leading hypothesis ties this shift to the unusually long childhood that humans experience compared to other primates. Young children who could already walk and move independently still depended heavily on adult protection and guidance. A silent, visual signal like tears would have been a far better strategy for getting help from a nearby caregiver than a loud scream, which could attract predators or hostile strangers. Tears allowed children to communicate need to specific people without broadcasting vulnerability to everyone within earshot.
There may also be a neurological basis for the split. A type of specialized brain cell called a spindle neuron, found in a region involved in emotional awareness, appeared relatively recently in human evolution and is far more abundant in human brains than in great ape brains. These neurons are also found in some whale and elephant species, suggesting that emotional complexity and large brain size may drive similar adaptations across very different animals through independent evolutionary paths.
Apes Do Grieve
The absence of tears doesn’t mean apes lack deep emotional responses. Gorillas have been observed engaging in extended mourning behavior when a group member dies. When a silverback named Titus died, other members of his troop stayed near his body for days. Some stared at the corpse, while others smelled, touched, or licked it. One young gorilla remained close to Titus for two full days. In another case, a young gorilla whose mother, Tuck, had died took care of her body and even tried to nurse from it.
Mountain gorillas in the Democratic Republic of the Congo displayed similar behavior upon encountering the body of a lowland gorilla that wasn’t even a member of their group. They formed a circle around the remains and groomed the body. These responses go well beyond simple curiosity. They suggest something closer to what humans would recognize as mourning, even without a single tear shed.
Why We Misread Ape Emotions
People naturally project human emotional patterns onto animals, especially primates. This tendency, called anthropomorphism, is so strong that it shows up on brain scans. When untrained observers watch footage of animals, their brains activate regions associated with projecting human-like qualities onto what they see. Primatologists, by contrast, rely more on sensory and motor processing to carefully interpret facial expressions and body language, leading to more accurate readings of what an ape is actually feeling.
This matters because viral videos and social media posts regularly describe apes as “crying” when they’re doing something quite different. A chimpanzee with watery eyes likely has an irritant or an eye infection, not emotional tears. A gorilla sitting quietly after a loss is grieving in its own way, through proximity, touch, and attention to the body, not through the tear-based signaling system that humans evolved. Recognizing the real ways apes express distress gives a more honest picture of their emotional lives than forcing them into a human framework.