Head to head
Monkey vs Ape
People use monkey as a catch-all for any non-human primate, but biologists draw a firm line between monkeys and apes. The two groups last shared an ancestor more than 20 million years ago, and the differences show up in the skeleton, the brain, and the way each animal moves through its world.
| Monkey | Ape | |
|---|---|---|
| Tail | Present in almost all species | Absent in every species |
| Group | Old World and New World monkeys, 250+ species | Hominoidea: gibbons, great apes, humans (~2 dozen) |
| Body build | Narrow chest, tail for balance | Broad chest, mobile shoulders, upright torso |
| Movement | Mostly runs on all fours along branches | Swings, climbs, knuckle-walks, or walks upright |
| Brain | Smaller relative to body | Larger and more folded |
| Size | Mostly small to medium | Medium to large; gorilla the biggest primate |
| Life history | Shorter life, faster breeding | Long life, slow breeding, long childhood |
| Examples | Baboon, macaque, capuchin, howler, mandrill | Gibbon, orangutan, gorilla, chimpanzee, human |
Monkey vs Ape: common questions
What is the simplest way to tell a monkey from an ape?
Look for a tail. If the animal has a tail, it is almost certainly a monkey; if it has none, it is very likely an ape. The rule is not quite perfect, because a few monkeys, such as some macaques, have only a short stub, but it works nearly every time. Beyond the tail, apes look broader across the shoulders and chest, sit and stand more upright, have longer arms relative to the body, and lack the muzzle-forward face of many monkeys. Size helps too, since the largest primates, the gorilla and orangutan, are apes, though small apes like gibbons overlap with big monkeys.
Are humans apes or monkeys?
Humans are apes. We sit firmly inside the group Hominoidea, sharing a tailless body, a broad chest, mobile shoulders, and a large brain with gibbons, orangutans, gorillas, chimpanzees, and bonobos, and our closest living relatives are the chimpanzee and bonobo, from which our lineage split roughly 6 to 7 million years ago. In strict cladistic terms humans are also monkeys, in the sense that the ape branch grew out of the Old World monkey radiation, so the group that contains all monkeys contains apes and therefore us. But in normal usage humans are apes, not monkeys.
Which is more intelligent, a monkey or an ape?
On the usual measures the great apes come out ahead. Chimpanzees, bonobos, orangutans, and gorillas make and use tools in the wild, solve novel problems, recognise themselves in a mirror, learn symbol systems in captivity, and pass on local traditions, and their brains are larger and more complex than any monkey brain. Some monkeys are very capable too, especially capuchins, which use stone tools to crack nuts, and baboons, which navigate large fluid societies, but no monkey matches a great ape on flexible problem-solving. Gibbons, the small apes, are bright but less studied and probably sit closer to the top monkeys than to the great apes.