I think some people are closed minded out of fear. They fear being 'led astray' by conflicting viewpoints. With others, it's an arrogance. They think they are right, and that is that. A lot of closed minded people are probably a combination of both.
However, I don't think people should fear being 'led astray'. Having an open mind and listening to different perspectives isn't necessarily going to lead you astray. You can still choose to believe what you always believed. But the value in hearing different perspectives is it gives you a bigger knowledge base to go off of, even if you don't agree with all of it. It makes you more informed, and better able to explain why you believe what you believe, and why you don't believe what you don't believe.
And consider this, by learning new information, you may ultimately come across information that supports what you believe anyways. You may find out that you were right all along...but now you'll know why you were right! Alternatively, you might find out why what you thought was wrong is wrong. Learning new things won't necessarily lead you astray at all.
But perhaps the best reason for an open mind is it gives you the opportunity to connect dots that you may not have even known were there. I can think of several things I've learned over the years, where taken as individual statements, they may be difficult to believe. However, if you connect the dots, you begin to see a bigger picture you didn't even know was there. I could probably mention a few things out of context here, and people reading this would probably think they were far-fetched. However, if you connect them together, suddenly they seem less far-fetched. It starts to make sense. This is why an open mind can be a good thing, even if you dismiss something you hear initially. At first, you might hear something that sounds far-fetched and not give it much more thought. Later down the road, you might hear something else that sounds kind of crazy, but it stays in the back of your mind. After a while, you hear something else that makes you think, "Hmm...that sounds similar to something I heard a while back. Perhaps the two things are connected. If so, that may mean that [insert topic here] I heard someone mention before may be connected too." Sometimes, seemingly unrelated topics may be connected without you even knowing it. But if you've had an open mind and learned a lot of perspectives about different topics, you may find yourself making connections between things you didn't even know were connected.
Ultimately, having an open mind won't necessarily lead you astray. If it did, it's possible you wouldn't even realize you were led astray because you may feel more enlightened because of it. A willingness to consider other perspectives makes you less arrogant (or at least seem less arrogant). Ultimately, I think you find yourself feeling more informed and more enlightened. Having an open mind doesn't prevent you from thinking on your own and drawing your own conclusions. It's possible that you could be led astray by having an open mind, because there are a lot of deceivers and false information out there. But if truth seeking is your goal and you analyze things first with an open mind and without jumping to conclusions, you have a good chance of finding the truth eventually. Of course, it's good to continue to have an open mind once you've found the 'truth', you know...just in case that 'truth' turns out to not be true afterall. J
Hey, at the very least, you'll being able to converse with a lot of different kinds of people at dinner parties.