If your dog is killed in an accident, is it okay to eat it? Jonathan Haidt, associate professor of psychology at the University of Virginia examines people's reactions to this sort of question to explore the interplay of emotions--such as disgust--and reason in the formulation of moral standards.
On the issue of dog eating he writes:
In my dissertation and my other early studies, I told people short stories in which a person does something disgusting or disrespectful that was perfectly harmless (for example, a family cooks and eats its dog, after the dog was killed by a car). I was trying to pit the emotion of disgust against reasoning about harm and individual rights.
I found that disgust won in nearly all groups I studied (in Brazil, India, and the United States), except for groups of politically liberal college students, particularly Americans, who overrode their disgust and said that people have a right to do whatever they want, as long as they don't hurt anyone else.
These findings suggested that emotion played a bigger role than the cognitive developmentalists had given it. These findings also suggested that there were important cultural differences, and that academic researchers may have inappropriately focused on reasoning about harm and rights because we primarily study people like ourselves—college students, and also children in private schools near our universities, whose morality is not representative of the United States, let alone the world.
He identifies four principles currently emerging in the field of moral psychology:
recently summarized this new synthesis in moral psychology with four principles:
1) Intuitive primacy but not dictatorship. This is the idea, going back to Wilhelm Wundt and channeled through Robert Zajonc and John Bargh, that the mind is driven by constant flashes of affect in response to everything we see and hear.
Our brains, like other animal brains, are constantly trying to fine tune and speed up the central decision of all action: approach or avoid. You can't understand the river of fMRI studies on neuroeconomics and decision making without embracing this principle. We have affectively-valenced intuitive reactions to almost everything, particularly to morally relevant stimuli such as gossip or the evening news. Reasoning by its very nature is slow, playing out in seconds. ....
2) Moral thinking is for social doing. This is a play on William James' pragmatist dictum that thinking is for doing, updated by newer work on Machiavellian intelligence. The basic idea is that we did not evolve language and reasoning because they helped us to find truth; we evolved these skills because they were useful to their bearers, and among their greatest benefits were reputation management and manipulation.
Just look at your stream of consciousness when you are thinking about a politician you dislike, or when you have just had a minor disagreement with your spouse. It's like you're preparing for a court appearance. Your reasoning abilities are pressed into service generating arguments to defend your side and attack the other. We are certainly able to reason dispassionately when we have no gut feeling about a case, and no stake in its outcome, but with moral disagreements that's rarely the case. As David Hume said long ago, reason is the servant of the passions.
3) Morality binds and builds. This is the idea stated most forcefully by Emile Durkheim that morality is a set of constraints that binds people together into an emergent collective entity.
Durkheim focused on the benefits that accrue to individuals from being tied in and restrained by a moral order. In his book Suicide he alerted us to the ways that freedom and wealth almost inevitably foster anomie, the dangerous state where norms are unclear and people feel that they can do whatever they want. ....
4) Morality is about more than harm and fairness. In moral psychology and moral philosophy, morality is almost always about how people treat each other. Here's an influential definition from the Berkeley psychologist Elliot Turiel: morality refers to "prescriptive judgments of justice, rights, and welfare pertaining to how people ought to relate to each other."
Most traditional societies care about a lot more than harm/care and fairness/justice. Why do so many societies care deeply and morally about menstruation, food taboos, sexuality, and respect for elders and the Gods? You can't just dismiss this stuff as social convention. If you want to describe human morality, rather than the morality of educated Western academics, you've got to include the Durkheimian view that morality is in large part about binding people together.
Read it all.