AllSides tends to attract some of the most rational thinkers around: people who want to see all sides of something before drawing a conclusion about it.

Does that sound like you? If so, you might get pretty annoyed at people who take a strong view that seems ill-informed.

The next time time you feel angry at someone who is loudly proclaiming a nonsensical viewpoint, let yourself feel affirmed by this fact: though that person thinks their opinion makes perfect sense, opinions are rarely rational.

More research confirming this fact seems to surface regularly. Check out the blog post by George Dvorsky, The 12 cognitive biases that prevent you from being rational. He goes into twelve of the many biases humans have, including:

• Confirmation Bias - seeking sources who agree with us
• Ingroup Bias - overvaluing the opinions of those we socialize with, ignoring the rest
• Gambler's Fallacy - believing past correlation equals future causation
• Post-Purchase Rationalization - subconsciously justifying ourselves with irrational views
• Neglecting Probability - you're more afraid of flying than driving, in spite of the statistics
• Observational Selection Bias - the bias that causes us to see red trucks everywhere once we're thinking of buy a red truck
• Status-Quo Bias - fear of change causes us to distrust alternatives
• Negativity Bias - we give more attention and credibilty to bad news
• Bandwagon Effect - unconsciously trusting the crowd's view, no matter how wrong the crowd is
• Projection Bias - assuming others experience the world as we do
• The Current Moment Bias - Dvorsky illustates this one well: "...a 1998 study showed that, when making food choices for the coming week, 74% of participants chose fruit. But when the food choice was for the current day, 70% chose chocolate."
• Anchoring Effect (aka The Relativity Trap) - this is where value something because the sign says it's 50% off, rather than considering whether that purchase price is worth it

Further explanation of these rationality blockers can be found at Dvorsky's post, and you might also be curious to read up on dozens more of them in this Wikipedia article.

If news of how hard it is to be rational gets you down, do not despair. There are ways to outsmart our own irrational opinions, as highlighted in this post about Jonah Leher’s book, How We Decide, which explores the science of human decision making in detail.