Domestic pigs, the kind portrayed in hot-pink neon above barbecue joints, curly tailed and carefree, have prodigious memories. In problem-solving with computers, they match wits with little kids and win. They are able to plan ahead, and they live in complex social communities. They recognise other pigs as distinct individuals.
Pigs aren’t just cerebral, though: they have heart. When others are in distress, they can express concern and act with empathy. A description of pig behaviours, derived from scientific experiments and compiled by Lori Marino of the Kimmela Center for Animal Advocacy and Christina M Colvin at Georgia Institute of Technology is so impressive, you might think it was about chimpanzees, elephants or whales.
We eat pigs, though, and we eat them on a scale unparalleled in comparison with the rate at which we consume other brainy mammals. According to the United Nation’s Food and Agriculture Organization, pork is the most consumed meat in the world.
Barbecue is a cultural obsession in many countries, as is bacon, whether served straight up or in more recent innovations such as bacon chocolate and bacon vodka. Plus, once satiated with real bacon, some might even retire to bed after brushing with bacon-flavoured toothpaste.
We value the taste of pigs far more than we value the lives of pigs. Exceptions include pig celebrities, whose personalities are known and cherished, and whom we assign to a different, protected, pet-like non-consumable status. Esther, a 650 lb ‘wonder pig’ who lives in a house with Derek Walter and Steve Jenkins in Ontario, Canada, is a ‘public figure’ on Facebook with more than 1.1 million followers.
Or consider Christopher Hogwood (named after the famed English conductor and musicologist), a pig who lived in a barn at the home of Sy Montgomery and Howard Mansfield in New Hampshire from his infancy until his death at age 14. Christopher grew to a size even larger than Esther, and through Montgomery’s memoir The Good Good Pig (2006) became a poster pig for porcine cognition and emotion.
Montgomery describes how a belly rub in the sun from her, or dinner leftovers from a local chef, plunged Christopher into a state of utter delight visible to all: he telegraphed this rapture through sound (‘unh-unh-unh!’) and body posture. At those moments, he became the ultimate mindful mammal, one who dwelled entirely in the present. But Christopher didn’t live only in the present any more than we do. He built nests, not in a rote instinctual way, but in fussy anticipation of his own needs for soft-hay comfort. His memory for individual humans – his own complex social community – was excellent.
Two young children, once neighbours, continued to visit him at irregular intervals even after they moved to another state. ‘He still remembered the little girls next door,’ Montgomery told me, ‘when they had been away not only for a pretty long time, but during a period of adolescent growth in which just a few months will make a big difference – in what you look like, how tall you are, what your voice sounds like, what you smell like.’ Christopher’s ‘voice became softer and lower’ when interacting with people who were visibly sad, a feat of perspective-taking that suggests an empathy response.
Of course, storytelling about pigs as individuals invites people to think differently about pork and bacon. But what does science – the kind of science reviewed by Marino and Colvin – say? That question has preoccupied me for several years.
Some science begins with the presumption that pigs are not particularly intelligent or empathetic animals. Two years ago, a group of swine researchers led by the animal scientist Sophie Brajon then at the Université Laval in Quebec published the paper ‘The Way Humans Behave Modulates the Emotional State of Piglets’.
The research is part of a corpus showing that the emotional state of animals, including farmed animals, biases their information-processing. Yet the conclusion reached, that gently handled pigs showed more positive emotional states than roughly handled or neglected ones, conveys a larger message: that we have a way to go before it’s the starting point, not the big reveal, that farmed animals have emotions and are affected by how we treat them.
A good deal of the science writing on pigs aims to increase awareness of pigs’ capacities so that they are treated better. The biologist Donald Broom and colleagues at the University of Cambridge discovered that pigs, with only five hours of experience, can use a mirror to find the location of a hidden object. Mirror-naïve pigs search behind the mirror to find the treat, but after five hours’ practice, 10 of 11 pigs turned away to find the real location of the savoury items within 23 seconds. (A fan blew the food smells away, so that smell cues didn’t confound the process.) This is a cognitive feat because both the concept of the food and its position must be remembered, as interpreted from the non-real-world view of the mirror.
In one study, the pigs were better than the toddlers at moving a joystick (by snout) to a target
Pig cognition is formidable. The biologist Candace Croney at Purdue University in Indiana described the cognitive research she’d done on pigs as a graduate student. She wasn’t, at the start, expecting much: ‘My understanding of pigs was that they were dumb, dirty animals,’ she said. The names she bestowed on her study subjects suggested she wasn’t expecting much in the way of cognitive ability. She called one pair of pigs Pork and Beans, another Hamlet and Omelette, and another, inevitably, Bacon and Eggs.
Croney’s careful research proved her low expectations wrong. In an ingenious experiment, she and her colleagues carried wooden blocks shaped into Xs and Os around the pigs. Only the O carriers fed the pigs. The pigs soon followed the O and not the X carriers – not exactly a surprise. Next, the researchers, no longer carrying wooden blocks, wore T-shirts marked with either Xs or Os, and the pigs transferred their knowledge to a new situation: they approached only the O-wearers. They ‘got’ the meaning of the symbol, flattened to two dimensions from three.
Croney also tested the pigs, along with young human children, on a computer exercise. The goal was to move a joystick to a target – by snout for the porcine study participants, by hand for the small-human ones. The pigs were better at it than the toddlers.
It is useful to know that pigs can and do reason out problems. But recent science, and storytelling, is also revealing that pigs have a running internal narrative going on. They reflect on what happens to them, and what the past meant. Indeed, they think, they feel, they solve problems, they exhibit individuality. Should we be eating pigs at all?