Are Chickens Smart? What Studies Show About Counting, Self-Control and Memory
Are chickens smart? Newborn chicks chose the larger of two hidden sets 65% to 70% of the time, and hens waited for a jackpot, but with equal surface area the chicks chose at chance. There is no chicken IQ. Each study, with journal, year and number of chicks.
Are chickens smart? Yes, smarter than most people think, but no one has measured a chicken IQ. Studies show that newborn chicks pick the larger of two hidden sets, hens can wait for a bigger reward, and a 2017 review found chickens comparable to other birds and mammals in several areas. One counting result shrinks when size cues are removed.
Below: each study with its journal, year and number of chicks, how a chicken’s brain compares with a raven’s, and what “chicken intelligence” can and cannot mean. The finding most pages miss: in one study chicks chose the larger set 67% of the time, but only 50% when the sets matched in surface area.
Key takeaways
- There is no chicken IQ. IQ compares people with a norm group of people, and no norm group exists for chickens.
- Number: newly hatched chicks chose the screen hiding three objects over two, 65% and 70% of the time in two tests of 15 chicks each (Rugani and colleagues, Proc R Soc B, 2009).
- Caveat: with 6 versus 9 objects and equal surface area, 18 chicks chose at chance, about 50% (Rugani, Regolin and Vallortigara, Frontiers in Psychology, 2011).
- Self-control: hens were impulsive in the standard waiting task and showed self-control when the larger reward was made especially valuable (Abeyesinghe and colleagues, Animal Behaviour, 2005).
- Brain: the red junglefowl, the wild ancestor of the chicken, has about 221 million neurons; a common raven has about 2.17 billion.
Are chickens smart, and how smart is a chicken?
A chicken is smart for a bird bred for food: it learns, remembers and responds to numbers and rewards. It has no score on any scale that compares animals.
IQ is a score that compares one person with a large sample of other people of the same age. Nothing like that exists for chickens, so “chicken IQ” is a figure of speech. Researchers test one ability at a time instead, and the sections below follow that. Our ranking of the smartest animals by neuron count and test scores uses the same rule.
Can chickens count?
Newborn chicks chose the larger of two hidden sets in tests, which suggests a basic sense of number. The result depends on the cues, as the 2011 study below shows.
In Rugani and colleagues (Proceedings of the Royal Society B, 2009), chicks were raised with five identical objects and tested on day 3 or 4. Objects vanished behind two screens, and the chick chose a screen.
In the first experiment, 15 chicks per test chose the screen hiding three objects over the screen hiding two objects, 65% of the time in one test and 70% in the other. The authors called this proto-arithmetic. A second group of 16 chicks, with the sizes of the objects controlled, still chose the larger set at about 65%.
Do chickens really count, or do they judge size?
Possibly size. When a later study made the total surface area or the outline length of two sets equal, chicks stopped preferring the larger one.
| Comparison | Size cues available | Surface area or outline equalised |
|---|---|---|
| 6 versus 9 objects | 67% | 50% |
| 5 versus 10 objects | 69% | 53% |
The authors wrote that the chicks succeeded only when non-numerical cues, such as total size, were available along with the numerical ones. So there are two honest readings. Chicks count small sets, as in 2009, and for larger sets they lean on size.
Can chickens wait for a bigger reward?
Yes, but only when the bigger reward is worth the wait. Hens were impulsive in the standard test and showed self-control when the larger reward was especially valuable, according to Abeyesinghe and colleagues (Animal Behaviour, 2005).
The hens could take a small food reward soon or a larger one later. In the standard version they took the small one. In a “jackpot” version they waited. The authors argue that the impulsive choice can be explained by how much value a delay takes away.
The abstract we could read does not state how many hens were tested, so we do not quote a number. For another animal with no IQ score, see are squirrels smart. For other farm animals, see our guides to pig IQ and cow IQ.
Are chickens as smart as other birds and mammals?
In several areas, a 2017 review says yes. Lori Marino reviewed the peer-reviewed work on chickens in Animal Cognition and concluded they are comparable to other birds and mammals in cognitive and social complexity.
The review covers cognition, emotion, personality and social behaviour. It is a review of other people’s studies, not a new test, and it does not give a score either. For a bird with a far bigger brain, see our guide to crow IQ and the news piece on the smartest bird in the world.
Where would your own score land?
Take the IIF-certified assessment and get your score with the scale it was measured on, the percentile it corresponds to and the confidence range around it — the three figures most online tests leave out.
Find your IQ score now! →How big is a chicken's brain?
Small. The red junglefowl, the wild ancestor of the chicken, has a 2.8 g brain with about 221 million neurons, according to the published counts in our smartest-animals study.
| Bird | Brain mass (g) | Neurons in the whole brain |
|---|---|---|
| Red junglefowl (wild chicken) | 2.8 | about 221 million |
| Common raven | 14.1 | about 2.17 billion |
A raven has about 10 times the neurons of the wild chicken. The domestic chicken is not in that table, so the junglefowl stands in for it. Neuron counts are a rough guide to capacity and not a test score. Our animal intelligence ranking shows how the species compare.
What would a chicken IQ test even measure?
A human IQ test samples several abilities and adds them into one score. The chicken studies each sample one ability, so they map onto a human test only loosely, and the scale cannot be set without a large sample of chickens.
| Study | What the chickens did | Nearest human test skill |
|---|---|---|
| Rugani and colleagues, 2009 | Chicks chose the screen hiding more objects, 65% to 70% of the time | Number sense |
| Rugani and colleagues, 2011 | Chicks chose at chance, about 50%, once surface area was equal | Number versus size |
| Abeyesinghe and colleagues, 2005 | Hens waited for a larger reward only in the jackpot condition | Self-control and delay |
These are the kinds of skills a human test samples, one at a time and without a norm group. That is why the honest word is “capable” and not “high IQ”.
Can you test your own memory like a chicken study?
Yes, with a short game. The chick studies tested whether an animal can keep track of what is hidden, and our brain games test the same skill in people.
Try the sequence memory test or browse the brain games hub. For an actual IQ score, take the IQ test. It is built and normed for people.
Quick answers
- Are chickens smart? Yes, at learning, number sense and waiting for value. No chicken IQ exists.
- How smart are chickens? Newborn chicks chose the larger of two hidden sets 65% to 70% of the time in the 2009 tests.
- What is a chicken’s IQ? There is no score. IQ compares people with a norm group of people.
- Can chickens count? Small sets, yes. With larger sets and equal sizes, chicks chose at chance in one 2011 study.
- How many neurons does a chicken have? The wild red junglefowl has about 221 million, against about 2.17 billion for a raven.
The bottom line
Chickens are smart enough to pick the larger hidden set, to wait for a jackpot and to learn socially, and a 2017 review ranks them near other birds and mammals in several areas. There is no chicken IQ, and the counting result weakens when size cues are removed. That is the honest summary: capable, measured one skill at a time.
Sources
- Rugani R, Fontanari L, Simoni E, Regolin L, Vallortigara G (2009). Arithmetic in newborn chicks. Proceedings of the Royal Society B 276, 2451-2460.
- Rugani R, Regolin L, Vallortigara G (2011). Summation of large numerousness by newborn chicks. Frontiers in Psychology 2, 179.
- Abeyesinghe SM, Nicol CJ, Hartnell SJ, Wathes CM (2005). Can domestic fowl, Gallus gallus domesticus, show self-control? Animal Behaviour 70(1), 1-11.
- Marino L (2017). Thinking chickens: a review of cognition, emotion, and behavior in the domestic chicken. Animal Cognition 20(2), 127-147.
- Neuron counts: the data table of our smartest animals study, built from 14 published papers.
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