Not so obvious fact: this is a far larger problem than it needs to be.
Our egos tend to complicate the situation by convincing us that we ought to defend our position no matter what; this most often serves to amplify the disagreement and generate avoidable animosity. Consider the following exchange:
Person1: I like the Red Hot Chili Peppers.
Person2: Me too. I like their real stuff though before they sold out with BSSM.
Person1: Before BSSM they were just a bunch of immature dorks. BSSM and after shows them actually growing up.
Person2: BSSM and after is just a bunch of cheesy radio pop.
Person1: If you bother to take a look at some of the pop on the radio you'll realize the difference. I bet you listen to all sorts of prog just to convince yourself that you rebel against mainstream music.
Person2: You're just a sheep that swallows whatever the record companies shove down your throat.
As you can see the dialogue has evolved from a musical discussion to a pseudo-musical-political shouting match. There are three easy steps that will allow you to reduce the probability that a difference of opinion will mushroom into something worse:
- Realize that the discussion is completely subjective. You're talking about opinions here so it makes no difference how many times you repeat yourself, the discussion is not guaranteed to come to an end.
- When stating your opinion frame it as a subjective opinion rather than fact in order to reduce the likelyhood that the person you are speaking to will feel even slightly challenged. You optimally want to make them feel that their opinion has merrit or at least is as good as any other.
- Explore the subject. Get the other person to talk about why they like what they like. Talk about your own reasons for liking what you like. Who knows- one of you might get the other to reconsider.
All three of these steps can be summed up in one sentence: suppress thine ego.