Are Sheep Smart? What the Face-Memory Studies Show, and What They Do Not

Are sheep smart? By the tests that exist, yes, though no one has measured a sheep IQ. In a 2001 Nature study, sheep remembered 50 other sheep faces for over 2 years. In 2011, seven sheep passed an attention-shifting task used with people and macaques. The claim that sheep match human face skills is disputed.

Below: each study with its journal and year, why researchers argued in 2019 about what the face results prove, and why “are sheep dumber than cows” has no tested answer. The finding most pages skip is that 2019 debate. Face-recognition scientists challenged the claim that sheep match human face skills, and the sheep researchers only partly defended it.

Key takeaways

• There is no sheep IQ. IQ compares a person with a norm group of people, and no such group or test exists for sheep.
• Faces: individual sheep remembered 50 other sheep faces for over 2 years (Kendrick et al., Nature, 2001).
• Photos: 8 sheep chose a learned portrait on 79.2% of trials, and on 66.5% when it was tilted (Knolle et al., 2017). Chance was 50%.
• Rules: 7 sheep learned a rule, remembered it for 6 weeks and shifted their attention from colour to shape (Morton and Avanzo, 2011).
• Herding: staying in a flock balances grazing against safety from predators (Ginelli et al., PNAS, 2015). It is not a sign of a small mind.

Are sheep smart, and do they have an IQ?

No. IQ compares one person with a large sample of people of the same age, and no such norm group or test exists for sheep.

So any “sheep IQ” you see online is a joke or a guess. Scientists test one skill at a time instead. Sheep are not in our smartest animals ranking, which uses only published neuron counts and test scores. For scale, an adult human brain holds about 86 billion neurons (see our human brain facts).

Can sheep recognize faces?

Yes. Sheep recognise individual sheep and people by their faces, according to Kendrick and colleagues (Nature, 2001). Their study showed that individual sheep can remember 50 other sheep faces for over 2 years.

The authors link this skill to brain regions in the temporal and frontal lobes that respond to faces, with more involvement of the right hemisphere. People have a similar set-up.

A 2017 study moved to photographs. Knolle, Goncalves and Morton (Royal Society Open Science) trained eight female Welsh Mountain sheep, aged 7 to 8, to choose one of four celebrity portraits over an unfamiliar face for a food reward. After training, the sheep chose the learned face on 79.2% of trials when it was shown front-on, and on 66.5% when the face was tilted. Each trial offered two faces, so chance was 50%.

The same sheep also picked out their handler from photographs on 71.8% of trials without any pretraining. That is a clear result for a small flock. The next section shows what it does and does not prove.

Do sheep recognize faces as well as people do?

That is disputed. The 2017 abstract said sheep have face-recognition abilities “comparable with those of humans” and non-human primates, and that wording drew a reply.

In 2019 Towler and five colleagues, who study human face recognition, argued that the data did not support the claim. They gave three reasons: no human results on an equivalent task, sheep accuracy lower than people’s, and a pattern hinting at different mechanisms.

Peirce, a co-author of the 2001 study, replied that the 2017 data do not support every claim, but that older work from the Kendrick lab supports them more strongly. Peirce also noted that tilting a face is weak proof of recognition, because a simple algorithm could pass that test.

Kendrick, who led the 2001 work, agreed that the 2017 conclusions were “somewhat preliminary” because of the few animals and faces. Kendrick added that sheep are better at sheep faces than at human faces, just as people are better at human faces.

What else do studies show about sheep intelligence?

Sheep can learn rules, not only faces. Morton and Avanzo (PLoS ONE, 2011) tested seven female Welsh Mountain sheep on discrimination, reversal and set-shifting tasks. The paper opens by noting that sheep do not enjoy a reputation for intelligence.

Every sheep learned to pick the bucket of the rewarded colour within 7 sets of 8 trials. Six weeks later they needed only 1 set to reach the same level again, so they remembered the right choice at least that long.

When the rule flipped, the sheep kept choosing the old colour. Then they bleated, pawed the researcher or ate weeds before they switched. The authors took this as a sign that the sheep had also learned which choice was wrong.

The hardest test was an attention shift. Sheep learned that colour mattered, then had to switch to shape. That switch took significantly more trials than switching to new colours, the same pattern the authors report in humans and macaques.

Why do people think sheep are dumb?

Flocking looks like mindless following, but measurements describe a trade-off. Ginelli and colleagues (PNAS, 2015) tracked large groups of grazing Merino sheep. They saw fast, avalanche-like regrouping events.

The team concluded that the pattern balances two needs: exploring ground to graze, and staying in a large group for protection from predators. Staying with the flock is therefore a strategy. The memory and rule tests above point the same way.

Are sheep dumber than cows?

No study ranks them, and no IQ exists for either species. Our cow IQ guide reports the only direct comparison we found: an old 1981 maze test in which cows did well against dogs, pigs, sheep and goats.

That test is described second-hand in a review (Marino and Allen, Animal Behavior and Cognition, 2017), and we did not read the original. One maze cannot rank two species.

What do we still not know about sheep intelligence?

• The samples are tiny: 7 sheep in the rule study and 8 in the photo study, all Welsh Mountain ewes.
• The tests used food rewards, so motivation and eyesight shape the results.
• No sheep neuron count is in our data table, so we make no brain comparison with other animals.
• There is no head-to-head test of sheep against other farm animals beyond one old maze.

If you want a number for yourself, take the IQ test. It is built and normed for people.

Quick answers

• Are sheep smart? Yes, at learning faces and rules. No sheep IQ exists.
• How smart are sheep? They remembered 50 sheep faces for over 2 years and switched a learned rule from colour to shape.
• Can sheep recognize faces? Yes, sheep faces and some human faces. How close that is to human skill is disputed.
• What is sheep intelligence like? It is real but measured in small studies, one skill at a time.
• Are sheep dumber than cows? Untested. One old maze favoured cows, and we only know it second-hand.

The bottom line

Sheep are smart in the ways a grazing flock animal needs: they remember faces, learn rules and keep what they learn. The strongest claim, that their face skill matches ours, is still open. More in our animal series: are rabbits smart, are chickens smart and human brain versus dog brain.

Sources

• Kendrick KM, da Costa AP, Leigh AE, Hinton MR, Peirce JW (2001). Sheep don’t forget a face. Nature 414, 165-166.
• Knolle F, Goncalves RP, Morton AJ (2017). Sheep recognize familiar and unfamiliar human faces from two-dimensional images. Royal Society Open Science 4, 171228.
• Towler A, Kemp RI, Bruce V, Burton AM, Dunn JD, White D (2019). Are face recognition abilities in humans and sheep really ’comparable’? Royal Society Open Science 6, 180772.
• Peirce JW (2019). Do sheep really recognize faces? Evidence from previous studies. Royal Society Open Science 6, 182157.
• Kendrick KM (2019). Response to ’Sheep recognize familiar and unfamiliar human faces from two-dimensional images’. Royal Society Open Science 6, 182187.
• Morton AJ, Avanzo L (2011). Executive decision-making in the domestic sheep. PLoS ONE 6(1), e15752.
• Ginelli F, Peruani F, Pillot MH, Chate H, Theraulaz G, Bon R (2015). Intermittent collective dynamics emerge from conflicting imperatives in sheep herds. PNAS 112(41), 12729-12734.
• Marino L, Allen K (2017). The psychology of cows. Animal Behavior and Cognition 4(4), 474-498, as reported in our cow IQ guide.