Is It True That Thinking About Reasons Improves Decision Making?

Most people are irrational in that we all fall back on intuitive systems at a certain point. We can't be bothered to work out the reasons for and against doing something or coming to a certain conclusion. So is it true that actually reflection, thinking about reasons, improves the quality of our decision making? And it's very doubtful that that's the case, at least in some context.