When I speak of reason or rationalism, all I mean is the conviction that we can learn through criticism of our mistakes and errors, especially through criticism by others, and eventually also through self-criticism. (Karl Popper, 1958/67)

In a previous article for Neurobox.ca, I wrote about disinformation and how we must place ourselves in the uncomfortable position of doubt in the quest to debunk it (See “Surviving the Disinformation Age“). To expand on this, I would like to call on astrophysicist, author and television personality Carl Sagan’s baloney detector guidelines to provide a more tangible tool to question information.

The Demon Haunted World is Sagan’s testimonial to the importance of scientific and rational thinking and a warning of the dangers of pseudoscience and irrationality. In the chapter, “The Fine Art of Baloney Detection,” Sagan supplies the reader with a long list of advice on how to recognize disinformation. This chapter has become a standard among skeptics and advocates of critical thinking. Here is my cheat sheet version.

  1. Question the EVIDENCE

As the scientific method dictates, conclusions must always be based on independent reproducible evidence whenever possible. If the evidence does not support the conclusion, the conclusion is wrong.

  • Cause and Effect: One of the golden rules of the scientific method is that correlation does not mean causation. Just because A came before B does not mean that A is responsible for B. For example, just because immunization occurs roughly at the age as the first signs of autism appear (12-18 months of age) it doesn’t make the two related. In fact, numerous large-scale studies have found no evidence to support the link between vaccination and autism in children.
  • Appeal to Ignorance: this is when we draw a conclusion based solely on lack of evidence to the contrary. “If you can’t prove me wrong, then I must be right.” The fact that we have not discovered life on other planets, does not mean that life does or does not exist in the universe.
  • Observational Selection: Or more commonly referred to as “cherry-picking.” This is when we only see evidence that supports our conclusions and suppresses the evidence that doesn’t.
  • Statistical Misconception: We are not all statisticians. However, having a basic understanding of statistics can be an important tool. The most common error is using too little data to draw a conclusion. For example,  if two people loved a movie and both gave a review, you can’t say that 100% of all people will love it. In other words, get curious about the numbers.
  1. Question the AUTHORITY
  • Appeal to Authority: A major part of accepting a statement is the credibility of the individual giving the information. That does not necessarily mean you should be suspicious of everyone, but the level of skepticism should be gauged to the individual’s credibility as an expert. There is a saying in the scientific community; there is no such thing as authority, only expertise.
  • Attack the Messenger: It has become far too common in the age connected knowledge to “attack the messenger” in order to discredit the message. But personal attacks don’t change whether the person is right or wrong.
  • The Straw Man: This is when a person’s statements are distorted, or even falsified, in order to attack the conclusion.
  1. Question RHETORIC:
  • Weasel Words, as Sagan puts it, is using words or phrases that mislead. This if often used in politics to deflect from negative impacts a policy may have. Fun fact (relatively), the Vietnam war was called a ‘police action’ for a long time. We all know it wasn’t the case.
  • Rhetorical Gibberish is another way to tint a message. This is when technical jargon is used in the hopes of looking like an expert. An expert who truly understands a subject should be able to put it into words that all of us can understand (see The Curse of Knowledge by Mélanie L. Sisley).


It is important to remember as human beings, we are hardwired to look for patterns and coincidence to alleviate uncertainty and stress. Overcoming this can be emotionally difficult, but boiling down Sagan’s insights into these few guidelines has helped me.  Furthermore, these tips work both ways. As well as being red flags, my cheat sheet prevents me from misleading myself and others. Hope this helps you too. Leave me your questions and comments. I love to hear from you.

Michael Shermer, science writer, historian of science, founder of The Skeptics Society, and editor-in-chief of Skeptic magazine, discusses baloney detection.

Other great baloney detectors are: