Humans are born credulous – we instinctively believe what people tell us, even with no corroboration. We are especially credulous about statistics or other information that sounds like objective facts. Unfortunately, we are not so scrupulous when it comes to accurately and non-misleadingly reporting facts. There is an enormous amount of disinformation in the world, particularly about politics and other matters of public interest. If the public is interested in it, there is bullshit about it.
I have noticed that this bullshit tends to fall into three main categories.
First, ideological propaganda. If you “learn” about an issue from a partisan source – for instance, you read about gun control on a gun control advocacy website, or you hear the day’s news from a conservative radio show – you will get pretty much 100% propaganda. Facts will be exaggerated, cherry picked, deceptively phrased, or otherwise misleading. Normally, you will have no way of guessing the specific way in which the information is deceptive, making the information essentially worthless for drawing inferences.
Second, sensationalism. Mainstream news sources make money by getting as many people as possible to watch their shows, read their articles, and so on. To do that, they try to make everything sound as scary, exciting, outrageous, or otherwise dramatic as possible.
Third, laziness. Most people who write for public consumption are lazy and lack expertise about the things they write about. If a story has some technical aspect (e.g., science news), journalists probably won’t understand it, and they may get basic facts backwards. Also, they often just talk to one or a few sources and print whatever those sources say, even if the sources have obvious biases.