Why are we outraged about eating dog, but not bacon?

Images of distressed, caged puppies on their way to be slaughtered at Yulin dog meat festival in China have caused outrage around the world. Angry Facebook posts, tweets and online petitions supported by the likes of Ricky Gervais and Simon Cowell direct us to gruesome photos of dead dogs, skinned and boiled and hung up on butchers hooks.

I too find myself heartbroken by these images. But as a vegan I find myself wondering why isn’t there more outrage in the world over the slaughter of other animals. For instance, each year in the US roughly 110m pigs are killed for meat. Where is the same public outcry over bacon?

The simple answer is emotional prejudice. We just don’t care enough about pigs for their needless suffering to pull at our heartstrings. As Melanie Joy, social psychologist and expert on “carnism” points out, we love dogs, yet we eat pigs, and there are simply no good moral reasons for such hypocrisy.

One popular argument is that we should care more about dogs because of their superior social intelligence. This twitter user is typical:

However this belief really just reflects the fact that people spend more time getting to know dogs than pigs. Many people have dogs as pets and through this relationship with dogs we’ve come to learn about them and care deeply for them. But are dogs really that different from other animals we eat?

Though obviously not identical, dogs and pigs are quite similar in all the features that seem to count morally to most people. They have similar social intelligence with rich emotional lives, both can use human-given cues to locate objects, both might be able to use a mirror to locate objects (though research suggests pigs might have an advantage here) and, of course, both animals have a deep capacity to suffer and a desire to avoid pain.

So whether you believe, like the philosopher Peter Singer, that sentience should be the basis of our assigning moral value to an agent, or you believe, like Peter Carruthers, that higher intelligence or the capacity to act according to moral principles should be the basis, then dogs and pigs seem to be on equal footing. Yet where are the global protests on behalf of pigs?

Best buddies.Alessandro Della Valle / EPA

As a psychologist who studies the way people think morally, I am sobered (and saddened) by the cold truth that people are often blind to the inconsistencies in their thinking, particularly when animals are involved. Andrew Rowan, director of the Center for Animals and Public Policy at Tufts University, once observed that: “the only consistency in the way humans think about animals is inconsistency”. His statement is increasingly being backed up by new psychology research.

How are people inconsistent?

For one, people allow the wrong factors to influence their judgements of an animal’s moral standing. People often think with their heart rather than their head. For example, in one recent study conducted by my lab (not yet published) we presented people with images of farm animals and had them decide how wrong it would be to harm them. Unknown to participants, however, they were either presented baby animals (baby chicks, for example) or adult animals (fully-grown chickens).

By a large margin people said it would be more wrong to harm the baby animals than the adult animals. And why? Additional measures showed it was because baby animals are cute and evoke feelings of warmth and tenderness in people, while adult animals do not. The intelligence of the animal had nothing to do with the moral value that was assigned.

While these results may not be terribly surprising, they do highlight a problem with our moral hardware. Our morals seem to be guided in this case by involuntary emotions rather than careful reasoning.

Second, we are inconsistent in our use of “facts”. We tend to think the evidence is always on our side – what psychologists call myside bias. In one study I simply had people rate their level of agreement or disagreement about a number of potential benefits of going vegetarian. The benefits ranged from environmental benefits to animal welfare, health, and financial benefits.

I thought people would be divided about the benefits of going vegetarian, endorsing some of the arguments but not all of them. This is not at all what I found. People did not simply endorse one or two benefits; they either endorsed all or none of them. In other words, people recruited all of the arguments that supported their foregone conclusions about eating meat or going vegetarian.

Thirdly, we are quite flexible in our use of information about animals. Rather than thinking carefully about the issues or the facts, we tend to endorse evidence that supports our desired views. In another recent study not yet published, carried out with Steve Loughnan from the University of Edinburgh, we had people tell us how wrong it was to eat one of three different animals. One animal was a fictitious, alien animal they had never encountered before; a second was a tapir, a strange animal that is not used for food in their culture; finally, there was a pig.

As smart as a pig – but not on the menu.Eric Kilby, CC BY-SA

All participants received the same information about the animal’s intelligence and cognitive capacities, but people only thought it was wrong to kill the alien and the tapir for food. For the pig, participants ignored the intelligence information when making their moral judgement. It is normal that we eat pigs – and this seemed to be sufficient to lower pigs’ moral value, despite their equal intelligence.

Thus, while the vegan inside me is puzzled to see people get upset about the use of dogs as food yet not think twice about chowing down on a pork chop, my inner psychologist is not at all surprised. Our moral psychologies are good at finding fault, but not when the spotlight is turned toward our own practices and preferences.

Jared Piazza does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.