The three questions rule
In a great article called “Give it five minutes” on Signal vs. Noise, Jason Fried talks about gut opinions:
A few years ago I used to be a hothead. Whenever anyone said anything, I’d think of a way to disagree. I’d push back hard if something didn’t fit my world-view.
It’s like I had to be first with an opinion – as if being first meant something. But what it really meant was that I wasn’t thinking hard enough about the problem. The faster you react, the less you think. Not always, but often.
I have recently discovered the same thing about myself, so I've started forcing myself to ask the other person at least three questions about their opinion. Forming those questions helps me think. Often, my gut negative opinion changes. Sometimes, the questions change the other person's opinion. There is no downside.