The Zoologist Jordi Casamitjana reviews the latest study by Lori Marino and Debra Merskin about the intelligence, complexity, and individuality of sheeps

It still surprises me that we need this sort of thing.

I know it should not surprise me as this is what happens in carnist societies where everyone who is not a human has been demoted to the category of object. But yet, it is so obvious to me. It’s not because I am a Zoologist specialising in animal behaviour (therefore, an ethologist), which allows me to see what others cannot see. I honestly think that everyone could see it if they were free to look with an open mind if they got rid of their indoctrination and prejudice. If they open enough their eyes and forget what you are supposed to see.

When you do that, and you look at a non-human animal, you just see another kind of person. Mighty,  tiny, spiny, slimy, furry, feathery…it does not matter which form, but still a person. Still as intelligent person as you are…or as stupid person as you also are, but, essentially, a variation of “you”.

What surprises me is that, every now and then, we need to employ the work of many scientists to prove what should be obvious to us just by looking. For instance, when you have seen a live sheep, do you really think that you have seen a packet of food, a clothes rack, or a piece of furniture? Of course not, you have seen a person, but your carnist indoctrination has forced you to qualify such person as one of a “lesser” importance. As one not as good as you; as one not as complex as you, as one not as intelligent as you. And it would take many teams of scientists to try to cleanse you from such cloudy vision and show you that the person you are looking at is just more or less as intelligent, emotional, or complex as you are.

This is what Dr Lori Marino and Dr Debra Merskin had to do. They have to spend a considerable amount of time and effort compiling all the research that has ever been done about the intelligence of sheeps (I haven’t mis-spelled them; I will explain at the end) and publish it in a paper titled “Intelligence, complexity, and individuality in sheep“. They reviewed the scientific and academic literature on sheep cognition and behaviour, starting with searching on the Web of Science Core Collection using terms relevant to intelligence, cognition, and behaviour, continuing with Google-based direct searches through all of the major peer-reviewed journals using similar general terms as well as key terms from published papers. In addition, they used these same terms to search ScienceDaily for relevant news items and peer-reviewed papers and conducted a complete search of the websites of the major authors in these fields for all of their relevant publications. Finally, they searched the reference section of each paper to find additional papers in additional journals to ensure that the overall search was comprehensive. In the end, they put everything they found in a single paper, with more than 150 scientific references (I would mention a few in this review, but for the full reference please refer to the original paper).

I believed I did not need to read this paper as I was already sure of its conclusions, but I decided to read it anyway because I thought it would be good to review it for those who should read it but have no time or opportunity. However, in the end, I did learn a few things about sheeps I did not know, so I do recommend everyone to read it.

For your convenience, the following is the review of a review of everything we know for certain about the intelligence of sheeps (and if you want to read another review of it from another ethologist, Professor Marc Bekoff has also written one).

If you still think you are more clever than a ram or an ewe, you must read this.

Sheeps are Winners

Flock of Staring Sheep By Laurinson Crusoe via Shutterstock (1039708483)

If you want to write an article that tries to correct the erroneous view people have about the intelligence of sheeps, you need two kinds of experts. You need experts on the views people have on sheeps, and experts on what is actually the intelligence of sheeps, regardless of how people see them. This is what the authors of this review are. 

Lori Marino is a neuroscientist, former faculty affiliate at the Emory Center for Ethics, President of the Whale Sanctuary Project, and Executive Director of the Kimmela Center for Animal Advocacy. She has written over 130 publications on dolphin and whale brain evolution and anatomy; intelligence and self-awareness; and the effects of captivity on social mammals, including cetaceans, elephants and primates.  

Debra Merskin is a Professor of Media Studies in the School of Journalism and Communication at the University of Oregon. Her research focuses on how the media and popular press represent animals, resulting in species stereotypes, and how these portrayals affect the lived experiences of real animals. 

Merskin is the perfect person to tell us how people indoctrinated by carnism see sheeps. In the paper, we read this: 

“Sheep have generally been considered useful working animals in literary-cultural contexts, serving as linguistic metaphors for people who are viewed as blindly following en masse with no mind of their own…The views of sheep described above are consistent with their continued use as commodities and create the psychological need to downplay their intelligence and individuality.”

The paper, using many references as proper scientific papers do, goes on to describe how sheeps are looked at by different cultures and religions — all of which make them look stupidly docile and submissive. However, it misses a very recent metaphorical use of sheeps in modern vernacular: Sheeple. In conspiracy theory slang, sheeple are people who are docile or easily influenced, and this is used as an insult against people who are not conspiracy theorists. As, in this context, I am definitively one of the “sheeple”, I found it very fitting that we can now use science to show how intelligent sheeps are, and therefore how much wiser would it be for people to become sheeple instead of the often-deluded conspiracy theorists — who, by the way, I believe are damaging the vegan movement to a considerable extent. 

We certainly need to elevate sheeps to a position of recognised intelligence, but we should not go too far and place them somewhere they don’t belong. They are just “regular” mammals like you and me, not super-creatures, and they are not primates or apes like us, so their intelligence will be a bit different than ours, as the problems they normally encountered while they were evolving would be slightly different than ours (for instance, we, primates, are frugivores so one of the problems we have to solve is to ID which fruits are edible and when, something that is not really a problem a herbivore would face; so, we are much better at this task, while they are much better at identifying edible leaves). 

They also have an anatomy perfectly designed for their lifestyle, which is different from ours. They don’t have grabbing fingers as all of us primates have, or prehensile tails as some of us do, as they did not evolve to live on trees. As the paper points out, because sheeps are prey animals living on fields, they have excellent vision and hearing, being able to see behind themselves without turning their heads, with wide visual fields of 270° to 320°. Sheeps also have an excellent sense of smell, and they can even mark where they go with their scent to help others to find them as they have scent glands between the digits on their feet. They can also smell the members of the opposite sex or their offspring better than we do. Rams use their vomeronasal organ to sense the pheromones of ewes and detect when they are in estrus, while the latter uses it for early recognition of their neonate lambs, which is crucial as mothers form strong and exclusive bonds with their offspring. 

In the sheeps’ world, sheeps are perfect creatures with all the intelligence and complexity they need to survive, and this is why they have survived for so long, even after humanity began capturing and domesticating them since 11,000 BCE (All breeds of domestic sheeps, Ovis aries, are descendants of the wild mouflon of Europe and Asia, Ovis orientalis, who still exist today). Sheeps are winners, not losers. 

The Intelligence of Sheeps

Sheep chewing on grass By Nikolay.Lugovoy via Shutterstock (1357302251)

The analysis of the intelligence of sheeps in the paper is divided into several chapters deconstructing the key components of intelligence: Learning and Cognition, Emotions, Personality, and Social Complexity.

As far as learning and cognition are concerned, the paper deconstructs them even further into executive functions, other learning and memory abilities, face perception and responses to Mirrors, and after quoting all the research done on these subjects, it concludes the following: “Sheep show competence in many cognitive domains including memory and discrimination capacity. They excel especially in executive function and face perception, performing on par with some primates. These are both high-level abilities based on a number of different neocortical functions, the prefrontal cortex for executive function and the temporal cortex for face perception within and across species”

Executive function has been assessed in adult rams and ewes using three standard tests: visual discrimination learning, reversal learning, and attentional set-shifting. These involve different experiments to see if they can tell apart colours, and they can. They can perform not only the discrimination tasks and reversals but also the most complex tasks (the intra- and extra-dimensional set-shifting tasks), like humans.  

As far as memory is concerned, research has shown sheeps have excellent general memory and learning abilities. Lambs can learn basic tasks in as few as two trials (Bremmer, Baggins, & Kilgour 1980), but they seem better at learning through sight than through sounds. Lee et al. (2006) showed that sheeps can learn and remember complex mazes (18- and 40-week-old sheeps could remember a maze for at least 22 weeks and that prior experience). Sheeps can also learn to discriminate between various flavours (Launchbaugh 1994; Vilalba & Provenza 2000 ), and they can even self-medicate (Vilalba et al. 2006). 

Sheeps are excellent botanists (better than humans who have not undergone several years of training in this discipline of biology). They can categorise plants at the species level (Ginane & Dumont 2010, 2011) and can classify food items at an even higher level, showing that they can create a hierarchical representation of food categories (Ginane & Dumont 2010, 2011). 

Perhaps one of the most interesting poofs of “social” intelligence is facial recognition, and sheeps are very good at it. In experiments, sheeps have demonstrated neural, perceptual, and social specialisation for faces. They prefer the faces of conspecifics to others and the faces of familiar sheeps to unfamiliar conspecifics (da Costa et al. 2004). They can even discriminate “the breed” and sex of other sheeps (Kendrick et al. 1995). In 2002, Kendrick et al. studied 20 adult rams and ewes and showed they were capable of remembering 50 other individual sheeps. They can also distinguish between photographs of sheeps with calm facial expressions and those with startled expressions (Elliker 2005), and they can also recognise the fear in another sheep’s expression (Tate et al. 2006). They can even tell apart human faces (Davis et al. 1998; Peirce et al. 2001), including celebrities (Knoll et al. 2017). The only test that sheeps seem not to be passing “as well” as primates is the self-recognition using mirrors (although more research may be needed on that). 

The Emotions of Sheeps

sheep in a petting zoo By MaxShutter via Shutterstock (570693613)

As far as emotions are concerned, the paper concludes the following: “Sheep have emotions that range across the spectrum and combine with cognition in complex ways. They show evidence of cognitive bias, emotional reactions to learning, emotional contagion (which may be a simple form of empathy), and social buffering. In the social realm, strong bonds between mothers and their offspring can last for several months.”

Ear posture appears to be an indicator of emotional state in sheeps, so it has been studied at great length.  For instance, Reefman, Wechsler, and Gygax (2009) observed the reactions of 15 sheeps in negative (separation from the group), intermediate (standing in a feeding area), and positive situations (being voluntarily groomed by a favourite human), and then they recorded continuously for up to 4 minutes several ear postures, relative eye aperture, cardio-respiration, body surface humidity, and temperature. The groomed sheeps had the fewest ear posture changes and the most relaxed ear postures, whilst sheeps in the negative condition had the most forward ear postures. 

Boissy et al. (2011) observed that horizontal ear posture corresponded to a “neutral” emotional state, ears positioned back during unfamiliar and unpleasant, uncontrollable situations (interpreted as fear), ears positioned straight up during negative but controllable situations (anger), and ears were asymmetric (one up and one down) when the sheeps were surprised.  

Fear has been well studied in sheeps, and is typically expressed by behaviours such as highly focused visual and auditory vigilance, immobilization (a “frozen” posture), fleeing/attempts to escape, and defecation (Bouissou et al. 1996; Rohmeyer et al.1992; Vierin et al. 2002).

Cognitive bias has also been studied in sheeps. This is a negative and positive judgement bias. For instance, negative judgement bias (sometimes referred to as pessimism) is the negative responses to ambiguous stimuli after a negative emotional experience, whilst positive bias (optimism) is the effects of positive emotional experiences on cognition. Doyle et al. (2011) found that exposure to long-term unpredictable aversive events affected the motivation of sheeps to approach a bucket associated with a discrimination task located in a neutral zone during a test. Destrez et al. (2013) found that exposure to chronically stressful situations led to more pessimistic judgement biases and learning deficits in lambs. 

The paper goes on with many other examples of emotional cognition (such as yawning), social buffering (when an individual reacts less negatively or intensely to stresses and fear-inducing situations when in the presence of conspecifics), mother-offspring relationships, and play, but the one that I found more interesting because I did not know about it was emotional reactions to learning. This is the emotional effect (such as excitement) of improving on a task apart from the reactions to a reward itself (in other words, being proud of yourself when you have learned something). This has been proven in cows, but Broom and Barone study this on sheeps. They suggest that the sheeps may have been aware of their own success in solving a problem. 

As far as social complexity is concerned, the authors conclude the following: “Sheep groupings are not homogeneous but hierarchical, dynamic, complex relationships shaped by individual personalities and many other factors.” Viewing sheeps as creatures who have lost their individuality and are unable to decide by themselves because they are in a herd would be the same type of error anthropologists would make if they saw humans in a city using public transport and concluded they are devoid of personality and free will. Perhaps this error comes from seeing herds of sheeps being moved by sheepdogs controlled by the whistles of a shepherd, but if you think about it, who shows more independent thinking, the individual sheeps who choose to stay with the herd to avoid danger, or the dog who “obeys” the shepherd and blindly follows instructions?

Sheeps Are People

One black sheep in a herd of white sheep By MP_Foto via Shutterstock (2295201653)

If the plural of person is people, then sheeps are people, because each one is a separate person with a separate personality. The paper has a whole chapter about this, which concludes with, “There is abundant evidence of personality traits in sheep, in particular, shyness/boldness and gregariousness. More research is needed on other potential dimensions and complexities of sheep personality, in particular, the more general personality concepts such as reactivity/anxiety.”

Here are some examples of such evidence: Tests of shyness and boldness (based on risktaking, reactions to novelty, and levels of exploration, often correlated with patterns of foraging, spatial distribution, and responses to other groups) such as those conducted by Murphy et al. 1994, and Sibbald et al. 2009). Also, in 2008, Michelena, Sibbald, Erhard, and McLeod studied the role of individual personality under conditions of increased feeding competition. They identified individuals as bold or shy based on their willingness to leave the group in an indoor exploration test, and they found that individuals with bold personalities were more likely to split into subgroups during grazing experiments on patchy grass, suggesting that individual personality can influence spatial organization. In 2009 Michelena et al. found that individual differences in boldness and the proportion of bold to shy individuals could affect the foraging decisions of the entire group. 

None of this will be new to farmed animal sanctuary carers, who would be very aware of the differences in characters between the individual sheeps, how they relate to each other and communicate emotions, and how they deal with problems in an intelligent way. Wanting to be part of a herd, and relying on each other for protection, is a clever choice if you are a herbivore in an open plain, so this is in fact a sign of intelligence as it solves the relevant problems efficiently. But this does not mean that each individual member of the herd is no longer an individual or that they have lost the ability to decide by themselves. It only means that several individuals cooperating for a common goal, and trusting each other, is a good thing sheeps have managed to recognise — I know many humans who have not learnt this lesson yet.

The paper ends with this conclusion: “We have identified a variety of findings from the scientific literature on learning and cognition, emotions, personality, and social complexity showing that contrary to popular views and representations of sheep as unintelligent and lacking in individuality or autonomy, they have several complex capacities… Our review contradicts historical perceptions of sheep that fuel and sustain contemporary media, popular culture, and farming practices.” 

I agree completely, and if you read the paper (as I hope you do because it’s very good and comprehensive), you will find plenty of studies to support such a conclusion. My only criticism of the paper is that perhaps, to honour such individuality of sheeps, the authors should have used the veganised plural of sheep with an “s” at the end, as I have been using in the entirety of this article, as this is one of the rules of veganised language I recently wrote about (and not a grammar mistake, but a purposeful departure from conventional grammar to avoid speciesist language). 

Sometimes, when the truth stares you in the face, but you still do not see it, you need to get a bunch of people pointing at it, deconstructing it, showing it to you from different angles, and telling you what it means by using all sorts of diagrams and calculations. If that is what it takes, such collective effort is worthy, because failing to do it will end up with someone being harmed. Failing to show people the truth about sheeps will result in people continuing to eat them and wear their skin (which is what wool is ). 

It still surprises me that, in the 21st century, we need this sort of collective teaching

But this is the way things are.

“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.