Capuchin monkeys are among the strongest candidates for the smartest monkeys in the world, but there is no scientifically accepted monkey IQ ranking. Intelligence is better compared through specific abilities such as tool use, memory, abstract reasoning, cooperation, social learning and communication. Capuchins stand out for sophisticated tool use, rhesus macaques for metacognitive-style uncertainty monitoring, baboons for relational reasoning, and marmosets for flexible cooperation.
This Top 10 is therefore an evidence-weighted comparison rather than an official scientific ranking. The exact order can change depending on which kind of intelligence matters most.
Top 10 Smartest Monkeys at a Glance
| # | Monkey | Scientific name | Best-known cognitive strength | Evidence note |
|---|---|---|---|---|
| 1 | Robust Capuchins | Sapajus spp. | Stone tools, tool selection, flexible foraging | Exceptional wild tool-use record, including archaeological evidence |
| 2 | Rhesus Macaque | Macaca mulatta | Memory monitoring and uncertainty judgments | Extensively studied in controlled cognition experiments |
| 3 | Long-Tailed Macaque | Macaca fascicularis | Stone-tool use and task-specific tool selection | Some wild populations use stones to process hard foods |
| 4 | Japanese Macaque | Macaca fuscata | Social learning and long-lasting traditions | Famous for food-washing and other local behavioral traditions |
| 5 | Guinea Baboon | Papio papio | Relational and analogical reasoning | Some individuals generalized same/different relationships to new examples |
| 6 | Common Marmoset | Callithrix jacchus | Cooperation and partner-specific social strategies | Recent experiments show flexible coordination with social partners |
| 7 | White-Faced Capuchin | Cebus imitator | Learned stone-tool traditions | Some Panamanian populations habitually use hammerstones and anvils |
| 8 | Spider Monkey | Ateles spp. | Spatial memory and route planning | Wild travel patterns suggest memory-guided movement between food sites |
| 9 | Vervet Monkey | Chlorocebus pygerythrus | Predator classification and alarm-call learning | Classic field experiments show predator-specific responses |
| 10 | Mandrill | Mandrillus sphinx | Tool modification and flexible learning | Tool modification is documented, but the evidence base is smaller |
What Is the Smartest Monkey in the World?
If one group has to be chosen, robust capuchins in the genus Sapajus are among the strongest candidates.
Wild capuchins use stones as hammers and anvils, choose tools according to properties such as mass and transport cost, and apply stones to different foraging problems. Archaeological work in Brazil has even recovered capuchin stone tools dating back roughly 2,400–3,000 years.
That combination of wild tool use, flexible selection and long-term material traditions gives capuchins an unusually strong case.
But “smartest” changes with the task. A rhesus macaque may be more impressive in a metacognition experiment, while a Guinea baboon may excel in relational reasoning and a marmoset in cooperation.
How Can Scientists Compare Monkey Intelligence?
There is no universal monkey intelligence test. Researchers instead compare performance across separate cognitive domains.
| Cognitive ability | What scientists test | Monkey examples |
|---|---|---|
| Tool use | Selecting or modifying objects to solve a physical problem | Capuchins, long-tailed macaques, mandrills |
| Memory | Remembering locations, objects, sequences or prior outcomes | Macaques, spider monkeys |
| Metacognitive-style monitoring | Adjusting choices when memory or perception is uncertain | Rhesus macaques |
| Abstract reasoning | Learning relations such as same/different and transferring rules | Guinea baboons |
| Social learning | Acquiring behavior from other group members | Japanese macaques, capuchins |
| Cooperation | Coordinating actions with a partner | Common marmosets |
| Communication | Using or responding to information-rich calls | Vervet monkeys |
Robust Capuchins — The Tool-Use Specialists
Robust capuchins such as Sapajus libidinosus are among the most technologically sophisticated monkeys known.
Wild populations use stones to crack nuts and other hard foods. They can also use stones when excavating roots or underground prey. Field experiments show that individuals consider properties such as stone mass and transport distance when choosing tools.
The strongest evidence comes from Brazil’s Serra da Capivara National Park. Archaeological excavations found capuchin stone tools that are thousands of years old, showing that nonhuman primate material culture can leave a long-term archaeological record.
This does not prove that capuchins are “more intelligent in every way.” It does show exceptional physical problem-solving and tool behavior.
Rhesus Macaques — Memory and Metacognitive-Style Monitoring
Rhesus macaques are among the most heavily studied monkeys in comparative cognition.
One especially interesting research area is metacognition: the ability to monitor the state of one’s own knowledge or uncertainty. In experimental tasks, rhesus macaques can use an uncertainty response or decline difficult tests when performance is likely to be poor.
Researchers remain cautious about interpreting animal metacognition because simpler learning mechanisms must be ruled out. However, transfer studies and experiments involving memory tasks provide evidence that at least some rhesus macaques can respond to internal states such as uncertainty or memory strength.
That makes macaques important models for studying the evolutionary roots of cognitive self-monitoring.
Long-Tailed Macaques — Specialized Stone-Tool Users
Long-tailed macaques are another strong example of flexible physical intelligence.
Some coastal populations use stones to open shellfish, nuts and other hard foods. Tool selection can depend on the target: different foods may be processed with different stone sizes or techniques.
This behavior is especially valuable because it occurs in the wild rather than only in laboratory tasks.
Not every long-tailed macaque population uses stone tools. The behavior depends on local ecology and learned traditions.
Japanese Macaques — Famous for Social Traditions
Japanese macaques are central to the history of animal-culture research.
At Koshima Island in the 1950s, researchers documented a young female macaque beginning to wash sweet potatoes. The behavior later spread through parts of the group. Japanese macaques have also been studied for stone handling, grooming traditions and other socially transmitted behavior.
Modern researchers debate exactly how much these behaviors depend on imitation versus individual re-innovation, but the Koshima observations remain foundational in the study of social learning and animal traditions.
The important point is that monkey intelligence is not only about solving puzzles alone. It can also involve learning within a social group.
Guinea Baboons — Relational Reasoning
Guinea baboons have produced some of the strongest evidence for abstract relational learning in monkeys.
In a well-known series of experiments, a subset of baboons learned to distinguish relationships such as same versus different. Several then transferred that rule to new visual examples they had never seen before.
One study found that the successful animals still retained this relational ability about a year later.
This is more than memorizing a particular image. It suggests that some baboons can learn and generalize abstract relationships under experimental conditions.
Common Marmosets — Cooperation and Social Intelligence
Common marmosets are much smaller than baboons or macaques, but body size is not a useful measure of intelligence.
Marmosets are cooperative breeders and live in tightly coordinated family groups. Experimental studies show that they can cooperate with partners and adjust behavior depending on social relationships.
A 2025 study found that marmoset pairs used flexible strategies in a cooperative task and adapted their behavior to partner identity. Social gaze, kinship, dominance and sex all influenced coordination.
This makes marmosets especially interesting for understanding the evolution of cooperation.
White-Faced Capuchins — A Second Capuchin Tool Tradition
White-faced capuchins belong to the gracile capuchin lineage Cebus, which historically appeared to use tools less habitually than robust Sapajus capuchins.
That changed when researchers documented habitual stone-tool use in white-faced capuchins on islands in Coiba National Park, Panama. Some individuals use hammerstones and anvils to process hard foods including seeds, crabs and marine snails.
Young monkeys require experience to become efficient, making the behavior useful for studying learning as well as physical skill.
Spider Monkeys — Spatial Memory and Route Planning
Spider monkeys depend heavily on fruit that is scattered unpredictably through large tropical forests.
Wild tracking studies suggest that their travel is guided by spatial memory. Individuals often move along highly direct routes toward food resources that are too distant to be visible from the starting point.
Researchers have proposed that in some situations spider monkeys may plan routes involving more than one resource location.
Recent experimental work also shows that spider monkeys can discriminate between different object sizes, adding to evidence that they make flexible visual decisions about food and other objects.
Vervet Monkeys — Predator Classification and Communication
Vervet monkeys are famous because classic field experiments demonstrated different responses to different alarm calls.
Playback experiments found that:
leopard alarms caused monkeys to run into trees
eagle alarms caused them to look upward
snake alarms caused them to inspect the ground
Young vervets initially respond more broadly and improve predator classification with age and experience.
This combination of categorization, learning and communication is one of the classic examples in primate cognition.
Mandrills — Tool Modification With a Smaller Evidence Base
Mandrills are included lower on this list because their cognition is much less extensively tested than that of capuchins or macaques.
However, a captive male mandrill was documented selecting sticks, breaking them into smaller splinters and using the modified pieces to clean beneath its toenails.
The observation is notable because it involves both tool use and tool modification outside a feeding context.
One individual observation cannot establish a species-wide cognitive ranking, but it demonstrates that mandrills can show flexible object manipulation.
Which Monkey Has the Highest IQ?
No monkey has a scientifically validated human-style IQ score.
Human IQ tests are designed around human language, education, symbols and problem-solving formats. Applying those scores directly to monkeys would not be scientifically meaningful.
Claims such as “a capuchin has an IQ of 80” or “a monkey has the intelligence of a five-year-old child” usually oversimplify very different cognitive abilities.
A better question is: Which monkey performs best in a particular type of cognitive task?
Are Capuchins Smarter Than Macaques?
There is no universal winner.
Capuchins have particularly strong evidence for sophisticated tool use and physical problem-solving. Macaques have an exceptionally deep experimental literature covering memory, uncertainty monitoring, social learning and decision-making.
If you value tool technology, capuchins may look more impressive. If you focus on experimentally tested memory and cognitive monitoring, rhesus macaques have the stronger research record.
Are Baboons Smarter Than Monkeys?
Baboons are monkeys. They are Old World monkeys in the family Cercopithecidae.
Guinea baboons stand out in particular because experiments have demonstrated relational matching and transfer of same/different relationships to unfamiliar examples.
Are Apes Smarter Than Monkeys?
Apes and monkeys are different branches of the primate order. Chimpanzees, bonobos, gorillas, orangutans and humans are apes, not monkeys.
Great apes perform impressively in many cognitive domains, but this page intentionally ranks monkeys only. Mixing chimpanzees or orangutans into a “smartest monkeys” list would be taxonomically incorrect.
Are Tarsiers, Lemurs and Lorises Monkeys?
No.
Tarsiers are haplorhine primates but not monkeys.
Lemurs are strepsirrhine primates native to Madagascar.
Lorises are strepsirrhine primates from Africa and Asia.
A list of the smartest monkeys should contain actual monkeys rather than every animal that belongs to the broader primate order.
Frequently Asked Questions
What is the smartest monkey in the world?
There is no official scientific winner, but robust capuchins are among the strongest candidates because of sophisticated stone-tool use, tool selection and flexible problem-solving.
What are the smartest monkeys?
Strong candidates include capuchins, rhesus macaques, long-tailed macaques, Japanese macaques, Guinea baboons, common marmosets, spider monkeys and vervet monkeys.
What is the smartest monkey species?
No species has a validated overall intelligence score. Robust capuchins such as Sapajus libidinosus are especially impressive in tool use, while rhesus macaques are exceptionally well studied for memory and metacognitive-style monitoring.
Which monkey has the highest IQ?
No monkey has a scientifically accepted human-style IQ score. Researchers compare specific abilities rather than assigning one universal number.
Are capuchin monkeys smart?
Yes. Wild capuchins use stone tools, select tools according to physical properties and show flexible problem-solving in several foraging contexts.
How smart are rhesus macaques?
Rhesus macaques perform well in memory, decision-making and uncertainty-monitoring experiments and are among the most extensively studied monkeys in cognitive science.
Can monkeys use tools?
Yes. Robust capuchins and some long-tailed and white-faced capuchin populations use stone tools in the wild. Tool modification has also been observed in a captive mandrill.
Can monkeys reason?
Some monkeys can solve tasks involving abstract relationships. Guinea baboons, for example, have learned same/different relations and transferred them to unfamiliar examples.
Do monkeys have culture?
Some monkey populations maintain socially learned traditions in feeding, tool use, grooming and other behavior. Japanese macaques and capuchins are classic examples.
Are chimpanzees monkeys?
No. Chimpanzees are great apes. They should not be included in a ranking of monkey species.
Explore More Monkey Rankings
Continue with 10 Rarest Monkeys in the World, Top 10 Cutest Monkeys in the World, and 10 Most Powerful Monkeys in the World.
Scientific Sources
Nature Ecology & Evolution — Three Thousand Years of Wild Capuchin Stone Tool Use
Journal of Experimental Psychology: General — Uncertainty Responses in Rhesus Macaques
Behavioural Processes — Metacognitive Responding in Rhesus Monkeys
Psychological Science — Relational Matching in Guinea Baboons
Royal Society Open Science — Stone Tool Use in White-Faced Capuchins
International Journal of Primatology — Spider Monkey Spatial Memory and Travel Planning
Science — Vervet Monkey Predator Classification and Alarm Calls
Final Answer
There is no official smartest-monkey ranking, but capuchins are among the strongest overall candidates. Their sophisticated stone-tool behavior is unusually well documented. Rhesus macaques stand out in experimental cognition and uncertainty monitoring, Guinea baboons in relational reasoning, Japanese macaques in social traditions and common marmosets in cooperation. The best scientific comparison is not “which monkey has the highest IQ?” but “which monkey excels at which kind of intelligence?”
