The saying goes "don't believe everything you read" (or read on the internet or watch on TV) because we often do and we generally shouldn't. How are we so easily duped when we supposedly know better?
Psychologist Dr Douglas LaBier points to a study that posits our brains are just that lazy:
So, what happens within our minds and emotions that make us receptive to lies, and then resistant to information that exposes the truth? A study led by Stephan Lewandowsky of the University of Western Australia explains part of what may happen. The researchers found that "Weighing the plausibility and the source of a message is cognitively more difficult than simply accepting that the message is true — it requires additional motivational and cognitive resources."
Basically, when presented with the option of fact-checking every statement made by a politician or newscaster, our brains just make a snap decision because it's easier. If the argument seems convincing, our brains like to believe it. Of course, we have our biases, and that plays into the problem as well. We like to be right and hear things that affirm our existing beliefs — another fun problem known as confirmation bias. David McRaney, author of the book and blog You Are Not So Smart, explains:
Confirmation bias is seeing the world through a filter, thinking selectively. The real trouble begins when confirmation bias distorts your active pursuit of facts. Punditry is a whole industry built on confirmation bias. Rush Limbaugh and Keith Olbermann, Glenn Beck and Arianna Huffington, Rachel Maddow and Ann Coulter — these people provide fuel for beliefs, they pre-filter the world to match existing world-views. If their filter is like your filter, you love them. If it isn't, you hate them.
So how do you make your brain actually care about taking the truth? That's not good news, either, as it involves making you brain work — something it clearly hates to do. The easiest method, however, is to consider a person's perspective in addition to their opinion or advice. This way you can at least consider a bias. Additionally, it helps to hear multiple sides of the argument so you have many perspectives. Of course, if you want to fact-check any controversial statements, we've got a guide to help you out. None of these options are easy, but if you want the truth you have to force your brain to work a little harder.
Why You're Likely To Believe Political Lies! [Psychology Today]