Related to: How An Algorithm Feels From Inside, The Affect Heuristic, The Power of Positivist Thinking

I am a normative utilitarian and a descriptive emotivist: I believe utilitarianism is the correct way to resolve moral problems, but that the normal mental algorithms for resolving moral problems use emotivism.

Emotivism, aka the yay/boo theory, is the belief that moral statements, however official they may sound, are merely personal opinions of preference or dislike. Thus, "feeding the hungry is a moral duty" corresponds to "yay for feeding the hungry!" and "murdering kittens is wrong" corresponds to "boo for kitten murderers!"

Emotivism is a very nice theory of what people actually mean when they make moral statements. Billions of people around the world, even the non-religious, happily make moral statements every day without having any idea what they reduce to or feeling like they ought to reduce to anything.

Emotivism also does a remarkably good job capturing the common meanings of the words "good" and "bad". An average person may have beliefs like "pizza is good, but seafood is bad", "Israel is good, but Palestine is bad", "the book was good, but the movie was bad", "atheism is good, theism is bad", "evolution is good, creationism is bad", and "dogs are good, but cats are bad". Some of these seem to be moral beliefs, others seem to be factual beliefs, and others seem to be personal preferences. But we are happy using the word "good" for all of them, and it doesn't feel like we're using the same word in several different ways, the way it does when we use "right" to mean both "correct" and "opposite of left". It feels like they're all just the same thing. The moral theory that captures that feeling is emotivism. Yay pizza, books, Israelis, atheists, dogs, and evolution! Boo seafood, Palestinians, movies, theists, creationism, and cats!

Remember, evolution is a crazy tinker who recycles everything. So it would not be surprising to find that our morality is a quick hack on the same machinery that runs our decisions about which food to eat or which pet to adopt. To make an outrageous metaphor: our brains run a system rather like Less Wrong's karma. You're allergic to cats, so you down-vote "cats" a couple of points. You hear about a Palestinian committing a terrorist attack, so you down-vote "Palestinians" a few points. Richard Dawkins just said something especi...