By Sarah “Steve” Mosko /Boogie Green
“Sheepish,” as defined in the Merriam-Webster dictionary, means “resembling a sheep in meekness, stupidity, or timidity.” Society as a whole seems to agree that sheep are none too bright, given the familiar insult that someone is dumb as a sheep.
But what do we really know about what goes on inside a sheep’s brain? And, if they aren’t as dumb as we’ve believed, should attitudes change about eating them, using them for experimentation, or their treatment by the wool industry?
Monkeys are both intelligent and evolutionarily close relatives of humans, the obvious choice perhaps for researching neurological human diseases marked by cognitive decline, like Huntington’s disease, Alzheimer’s dementia and schizophrenia. However, many people question the morality of using primates for research expressly because of their intelligence, plus primates exhibit complex behaviors which make them difficult to manage in research settings.
Because sheep are docile and easily handled, but also have large mammalian brains with a human-like convoluted cortex, scientists have taken interest recently in their intelligence, considering them a possible model for studying neurological diseases. What they have discovered might surprise you.
“Executive functions” refer to complex managerial abilities, like planning, memory and problem solving, which control other cognitive functions and are commonly used to measure the extent of cognitive impairment in neurological diseases. In 2011, University of Cambridge scientists reported a jaw-dropper, that domestic sheep performed similarly to humans and Macaque monkeys on sensitive tests of executive functions.
The researchers tested for specific executive skills called reversal learning and attentional set shifting using runways with choice points, one side leading to a food reward, the other not.
The sheep easily learned to discriminate between colored buckets to earn a reward, i.e. only the choice with the green bucket offered the reward, not the yellow bucket. And furthermore, sheep remembered the correct choice six weeks later. More importantly, they demonstrated reversal learning, meaning they could learn to reverse their choice when the experimenter reversed which color bucket would hold the reward.
Sheep could even do the same task when the discrimination was made tougher by challenging them to figure out if it was the color (blue vs. yellow) or the shape of the receptacle (bucket vs. cone) that cued where the reward would be.
Attentional set shifting tasks are both harder and especially sensitive to frontal lobe impairment in humans. They require first learning stimulus discrimination rules, like pay attention to just color while ignoring shape, and then being able to adapt when the rules are changed.
To the researchers’ surprise, the sheep passed all tests of attentional set shifting with flying colors. In the simpler task, they had to learn to stick with color as the relevant stimulus dimension when blue and yellow buckets were replaced with purple and green cones, and they were able to later reverse this learning too.
In the toughest challenge, they had to first learn to attend to color, irrespective of shape, then switch to attending only to shape and ignoring color, and finally to reverse back again to attending only to color. This task is challenging for humans too. The researchers surmised the sheep might employ a strategy similar to what humans use.
By the way, though dogs also perform well on tests of reversal learning, we don’t know yet if attentional set shifting is within their capabilities, according to canine intelligence expert Norton Milgram at the University of Toronto.
Other recent investigations shed light on the memory skills, emotional lives and peer relationships of sheep.
Friendship, as humans conceive it, requires being able to recognize and remember individuals. The most extensive work on sheep memory has been done by British behavioral neuroscientist Keith Kendrick who, using facial photos, has shown that sheep’s abilities to recognize and remember faces rival that of humans. In Kendrick’s testing apparatus, sheep are shown two sheep faces at a time and press a panel with their nose to demonstrate their choice, earning a food reward for the correct one.
Not only can sheep discriminate between faces (either of sheep or of humans) that differ by only 10 percent, they can still remember 50 different sheep faces for at least two years. Kendrick suspects that sheep might even be able to form a mental image of a familiar face not presented to it, akin to when humans think about someone they know.
Friendship also implies differences between sheep and preferences for certain individuals. By and large, sheep are somewhat fearful of humans and tend to keep a distance, perhaps adding to a human perception that they all seem the same. However, research shows they have individual personalities. For one, they differ measurably from one another on the dimension of shyness and boldness.
They are also highly gregarious among themselves and demonstrate preference for faces of sheep with which they are familiar. Their reward in face preference experiments could be access to the individual whose face they chose.
Just like humans, sheep read emotions from visual facial cues. When stressed, their eyes protrude showing more of the whites, pupils dilate, nostrils flare, and the ears flatten. Kendrick reported that sheep not only recognize stress in other sheep from photos, but they prefer calm faces to stressed ones.
Sheep also prefer pictures of humans with smiling faces to those sporting angry expressions though, like other animals, sheep lack the lower facial musculature needed to smile as humans do.
While we cannot really know how similar are human friendships to preferences sheep exhibit for certain peers, we do know that sheep always stay in visual contact with other sheep and become distressed when isolated from their group. Just showing an isolated sheep photos of other sheep is calming.
Furthermore, farmers know that keeping sheep with their flock-mates is as important to successful domestication as adequate food and hygiene.
Most of the world’s wool comes from Australia where Merino sheep are farmers’ top choice because their wrinkly skin increases wool yield. However, the wrinkles collect urine and other moisture, attracting blowflies that lay eggs in the skin folds. The hatching maggots can literally eat the sheep from the inside out, a horrific condition called flystrike.
A controversial practice to prevent flystrike called mulesing (pronounced mule-zing) is legal in Australia. To create a bare rump area, farmers use hand shears on lambs a few weeks old to literally carve off the wool-bearing skin from around the anus to the top of the hind limbs. The tail is docked and skinned too.
Recent figures from the Australian Wool Exchange indicate that 90 percent of Australian wool still comes from mulesed sheep, and only 14 percent of the lambs are given anything for pain relief during or after the procedure.
In 2004, the Australian wool industry promised to phase out mulesing by 2010, but later reversed position. Several retailers are boycotting Australian wool as a result, including H&M, Gap, Liz Claiborne, Abercrombie & Fitch, and Perry Ellis.
New Zealand implemented a voluntary phase-out of mulesing in 2010. An independent accrediting body’s Zque label was developed to assure that wool came from sheep which were not mulesed and that environmentally sustainable farming practices were followed too.
The export of live sheep to the Middle East and South East Asia on ships in crowded, unsanitary pens is another dark side of Australia’s wool industry. Australia’s Standards for the Export of Livestock allows for pens too small to allow the sheep to turn around throughout voyages that can last many days. According to Animals Australia (Australia’s foremost animal protection organization), millions of sheep are forced onto the grueling journey each year just so they can be slaughtered Halal style – throats slit while fully conscious – as dictated by Islamic tradition. Thousands die in transport. Furthermore, the animals suffer appalling abuses and unnecessarily brutal slaughtering at destination countries which lack animal welfare protections.
Bills introduced by animal welfare groups in 2011 to end live sheep transport were defeated by the Australian House of Representatives. Another attempted ban on live animal exports was just introduced in May.
These observations on the intellectual and social capabilities of sheep, and their treatment in the wool industry, highlight one example of how very muddy for humans is the question of what moral standing should be accorded animals in general.
We have no way of knowing how animal pain and suffering compares to our own or whether intelligence enhances or blunts the experience of suffering. Society’s approach to using animals for food, for research, or for their hides lacks a rational moral compass and often seems based on nothing more than cloudy rules, like the “cuter” they appear to us or the more they resemble ourselves, the less acceptable it is to put animals to such uses.
For example, does knowing that sheep intelligence might rival that of monkeys mean sheep too should be spared experimentation, or do we conclude instead that sheep “behave” enough differently from humans that their intelligence and suffering are irrelevant? Or, what if sheep proved intellectually superior to dogs? Would we eat dogs instead?
Like the research described here, the little we know about the mental lives of animals derives largely from studies aimed at better understanding or helping ourselves, not them. Our seeming lack of unselfish curiosity about them reveals our own unease about what we might find. Hopefully the day will come when we muster the courage to genuinely care what existence is like for our fellow animals and to treat them with the respect and compassion that good conscience dictates.
In the meanwhile, given what just a handful of studies on sheep have already revealed, there’s no getting around the fact that humans have confused sheep’s docility for stupidity. Merriam-Webster should revise their definition of “sheepish” accordingly.
Sarah “Steve” Mosko is a freelance writer focused on environmental, human health and animal rights issues. She is a psychologist and sleep disorders specialist with a solid basic science research background which enables her to bring the latest science on a given topic to the general public. Though she grew up in San Diego, she resides presently in Orange County. Others articles by her can be read at www.BoogieGreen.com.