The decision about whether to eat meat has a moral dimension to it. The animals that we use for food are complex creatures. Deciding to eat them means accepting that they will be killed so that you can eat them.
That is not to say, of course, that people grapple with this decision at every meal, but in some way everyone has to make some decision about whether to eat animals. And before I go any further with this discussion, I should mention that I have been a vegetarian for about 10 years now for a combination of economic, health, and moral reasons.
An interesting question about eating meat involves how people grapple with the issue that many animals people eat are reasonably intelligent creatures. An interesting paper in the February, 2012 issue of Personality and Social Psychology Bulletin by Brock Bastian, Steve Loughnan, Nick Haslam, and Helena Radke suggests that when people eat meat, they tend to downplay the minds of the animals that they eat.
In one simple study, the researchers asked (meat-eating) participants to rate how willing they were to eat a variety of animals ranging from houseflies, to fish, to chicken to elephants to gorillas. They also rated the how strongly each of these animals had a number of mental abilities such as feeling hunger, fear, and pain, and having self-control and planning abilities. There was a systematic relationship between the animals people choose to eat and their beliefs about the minds of the animals. People were much less willing to eat animals that they believe have complex mental abilities than to eat animals that do not have complex minds.
Of course, this alone might just mean that the animals that people choose to eat are the ones that are not so smart. In another study, meat eaters were asked to think about cows and sheep. Some of them thought about these animals living an idyllic life on a farm. Others thought specifically about these animals growing up on a farm and then being killed for food. Later, they also rated the mental abilities of the animals. When people thought about the animals as food, their ratings of the mental abilities of the animals were lower than when they thought about the animals living on a farm.
It isn’t just thinking about animals being used for food, though. In one final study, all of the participants had to write about the process of raising and butchering animals for food. All of the participants thought they were going to do a food sampling task after writing the essay. Half of the participants were told they would be eating fruit during the food sampling, while others were told they would be eating beef and lamb. Finally, participants rated the mental abilities of cows and sheep. The group that was about to eat meat gave much lower ratings of the mental abilities of cows and sheep than the group that was about to eat fruit.
These studies suggest that people who choose to eat meat have to grapple with the moral dilemma of eating an animal with a brain whether they realize it or not. Because of the importance of eating to our lives, we think about food animals as less complex than other animals. This effect is particularly strong in the context of meat eating.
Of course, this mechanism is not special to eating. There are lots of situations in life that cause different goals and moral values to come into conflict. Eating a piece of chocolate may conflict with a diet. Buying a new car may conflict with the desire to save for a new home. Research that I did with Miguel Brendl demonstrates that, when one goal becomes highly engaged, we change our attitudes about things that would conflict with that goal to make them less attractive.
So, generally speaking, we have mechanisms that help us to satisfy our goals, in part by discounting the attitudes we hold that might get in the way of those goals.