You’re just fake news!: Faulty Logic in Health Information

In the social media universe, the world is black and white. Memes make bold claims about how to easily solve the world’s problems. But when you really stop to think about the claims being made, you may find them riddled with errors in reasoning. The more simplistic and catchy the claim is, the more you need to evaluate it for errors. These errors are known as logical fallacies, and they can be easy to miss because they trigger our emotions and appeal to our desire to have simple solutions to complex problems. Logical fallacies can be innocent mistakes, or they can be deliberately used to manipulate you. 

Common Logical Fallacies in Health Information

There are many logical fallacies. This post contains a sampling of fallacies we’ve seen in health information. I am providing examples that I think best fit each category, but you may find the same fallacy fits in multiple categories. 

  • Ad hominem attack: An ad hominem attack is an attack on the character of the source of information rather than an attack on the claim of the information. This weakens your argument because, while sources do need to prove they are experts on the subject, the attack doesn’t even attempt to discredit the claim. During COVID-19, news outlets reporting the grim details of the pandemic were frequently dismissed as “fake news” by people who disagreed with the outlet’s perceived political stance regardless of the truth of the claim. Calling something “fake news” encourages others to dismiss the claims. Dismissal of credible claims because they don’t come from your preferred source can be detrimental to your health.
  • Appeal to authority: There are countless memes that place a quote or an idea with a photo of a celebrity. This is an appeal to authority because the creator of the meme is trying to equate someone’s celebrity status with the authority to speak on health matters. A celebrity isn’t qualified to speak about health information just because they’re famous. Also, that celebrity may not have said anything similar to what the text claims it did, and the celebrity may not even agree with the claim. Anyone can put words with an image.
  • Appeal to ignorance: In this case, someone is appealing to your fear of the unknown, which is very easy to do with health information. The COVID-19 pandemic was ripe for this appeal because it was a new virus and the treatments had to be developed swiftly. The appeal to ignorance is common among groups attempting to encourage COVID vaccine hesitancy when they urge people not to get the vaccine because, “We don’t know the long-term effects.” It is true that we do not have years of evidence of human clinical trials at this time, but the claim ignores the 20 years of research and testing that went into the coronavirus vaccine development (COVID-19 is not the first coronavirus we’ve encountered), the decades of research on vaccine safety in general, and the evidence we have about the negative health impacts of COVID-19. Those claims also continue to ignore the evidence we have from more than 6 billion doses of vaccines administered across the world since human trials and vaccination efforts began in 2020 (Bloomberg, 2021). When you have questions about a health decision, that’s when you speak to your physician to examine all of the evidence for your particular situation.
  • Bandwagon: If you’ve heard the expression “jumping on the bandwagon,” you probably know it means following along with everyone else and doing what they’re doing. The logical fallacy is somewhat similar. If a lot of people share or like something, you are likely to believe it is true. You are jumping on the bandwagon of believing the claim. And you’re probably going to like and share it, too. This can easily happen with well-intentioned information; for example, if someone shares a story about the health benefits of a food or medication or diet and you see it has circulated a lot and people are liking it, you may believe it’s true and share it to help others stay safe and healthy. You have no reason to doubt it because someone would’ve called them out by now or the information would’ve been taken down by now if it was false, right? Unfortunately, it doesn’t work that way on social media. Misinformation is discovered after it has been widely shared, and once people share the information, it never truly disappears on any social media platform. You still need to evaluate the claim’s credibility even if it has been widely shared.
  • Causal: This is a common fallacy with health information because people assume when two things happen in close proximity, the first thing causes the second thing. This is a common fallacy when you’re trying to lose weight and try a fad diet which is followed by weight loss. The weight loss could’ve been due to the diet, but perhaps it was due to increased exercising or paying more attention to how much food you ate rather than the specifics of the diet itself. People tend to do multiple things at the same time when trying to lose weight. This is also a common fallacy with the yearly flu shot. Someone gets their flu shot, gets the flu a day or two later, and assumes the shot caused the flu. This may lead the person to never get the flu shot – or any other voluntary shot – again. But it’s possible this person was infected prior to getting their shot and it took a few days to show symptoms. Perhaps this person was ignoring the symptoms prior to getting a vaccine but paid special attention to the symptoms because of the vaccine. There is also the mistaken assumption that an immune response with flu-like symptoms is the flu, but that’s an issue for another post. 
  • False equivalency: This fallacy is “comparing apples to oranges,” or comparing two things that are not comparable. During COVID-19, we have seen this fallacy when comparing public health measures necessary to contain a pandemic to Nazi Germany controlling citizens. A pandemic and public safety measures meant to keep people alive are not the same as a dictatorship and Holocaust and measures meant to kill people. We have also seen people opposed to wearing masks and opposed to vaccine requirements co-opting the “My body, my choice” slogan of abortion rights activists. Again, the situations are different. Pandemic health measures to prevent you from infecting multiple people with a virus that could kill them is different from abortion and pregnany which are not contagious viruses that can spread throughout the community.
  • Hasty generalization: When we draw conclusions based on limited evidence, we make hasty generalizations. For example, we may think, “I got COVID and hardly had any symptoms, and so did my friend, so COVID really isn’t anything to worry about.” Two people are not representative of the entire population. You and your friend are likely (thought not always) similar in demographics, health, and socioeconomic status. Making this kind of hasty generalization leaves you vulnerable to health issues, and it may encourage you to not take precautions to protect others who will not be so lucky if they get sick.
  • Red herring: This fallacy uses an issue that is largely irrelevant to distract you from an important, often contentious issue. One popular meme that circulated in the last few years asked why insulin is so expensive when Narcan is free. This circulated after outrage over rises in the cost of insulin. People were rightly upset about a life-saving medication costing so much money. This should have led to larger debates about healthcare costs in the U.S., but instead this meme tried to distract people from the important issue – the systemic problems with healthcare in the U.S. – by creating an “us (people in the U.S. who need life-saving medication) vs. them (people who overdose on drugs)” mentality. These are two separate issues. Treating overdoses and drug addiction has no bearing on how the U.S. health system operates or its drug costs. This can also be an example of a false equivalency fallacy.

Additional Resources

Logical fallacies can be hard to spot. You must think critically about and question the information you consume and not get caught up in an emotional reaction. Here are some additional resources to help you spot logical fallacies and critically evaluate information.

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Join the Conversation


  1. This is one of my favorites yet. There are so many logical fallacies in the arguments we see against any practice that could help us end the COVID-19 pandemic. If I hear one more person say “I prefer to do my own research’ …. Unfortunately, confirmation bias tends to rule their research, so they end up more firmly entrenched in their mistaken beliefs than before.

    Liked by 1 person

    1. The “I prefer to do my own research” comment is a killer for me. That’s wonderful that people want to “do their research,” but they must actually do research rather than just confirm their own biases. They need to know how to do research and what sources to trust to get correct answers, even if those answers don’t confirm biases.


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