What is Pseudoscience? Learn to Objectively Evaluate Science

From the lecture series: Your Deceptive Mind — A Scientific Guide to Critical Thinking Skills

By Steven Novella, Ph.D., Yale School of Medicine

What is Pseudoscience? Pseudoscience goes beyond just making a few errors or a few sloppy practices—the methods are so flawed that the entire endeavor is suspect. They have the patina of legitimate science, but something has gone terribly wrong.

(Image: life_in_a_pixel/Shutterstock)

What is Pseudoscience: Working Backwards

The most prominent feature and the one that often determines much of what is flawed about pseudoscience is that it tends to work backward from desired results, rather than following logic and evidence where it leads. This is also referred to as “motivated reasoning.” If we know where we want to get cognitively, human beings are very good at getting there, at backfilling in justifications, making evidence fit into preconceived notions. So, essentially, pseudoscience starts with the conclusion and then works backwards from there, rather than open-mindedly and fairly going forward from the evidence wherever it may lead.

This is a transcript from the video series Your Deceptive Mind: A Scientific Guide to Critical Thinking Skills. Watch it now, on The Great Courses Plus.

Burden of Proof

Pseudoscientists often shift the burden of proof onto others. They might say something like, “Prove my theory wrong,” or “If you can’t prove my theory wrong, then you must accept it as correct.” But in fact, proving their theory wrong or at least attempting sincerely to do so should be their job. It’s their theory, their claim. The burden of proof is entirely upon them to show that their theory is correct because it has survived attempts at falsification and that no alternate theory, especially a simpler one, can also explain the data that they are presenting.

Image of a Phrenology chart
An 1883 phrenology chart. Phrenology is a pseudomedicine focused on measurements of the human skull, based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions (Image: By Unknown – People’s Cyclopedia of Universal Knowledge/Public domain).

Confirmation Bias

Pseudoscientists also commonly fall prey to confirmation bias, which is perhaps the most powerful bias that affects our thinking when we’re assessing different ideas. Confirmation bias is a process of looking for supportive evidence that leads to conclusions we wish to be true. This gives us a false sense of, “where there is smoke there is fire.” If my theory weren’t correct, how could this be? How could there be so much evidence that appears to support my argument?

But confirmation bias leads to cherry picking of only the evidence which supports one’s own theory. You have to collect data in a systematic way to know if it really does support a theory. This favoring of positive evidence, regardless of quality, is therefore, a key feature to look out for in a pseudoscience.

The flip side of that is that negative evidence, regardless of quality, is also dismissed. Therefore, for example, a scientist may look at a study which confirms their belief and accept it uncritically, while looking at another study that seems to contradict their evidence, they will delve into the details and look for subtle flaws, look for reasons to reject the study as solid or conclusive because they don’t want to accept its conclusions.

For any particular question, especially now that so much scientific evidence is out there, thousands of new papers are being published every year in every field. There is so much noise, if you will, that if you are truly dedicated to supporting any notion, you can probably find studies in the peer reviewed, published literature that seem to support that position. Only by looking at all the data systematically though, can you know if the bulk of evidence or the consensus of evidence really supports your position.

Learn more about specific biases should you be on the lookout for when viewing scientific studies

Congruence Bias

True scientists consider alternate theories and not just their pet theory, but pseudoscientists will often simply make attempts at proving their pet theory correct and will only in a very perfunctory manner address other theories which might also explain the observations that they’re making. Otherwise, you fall prey to the congruence bias, the tendency to only test your own hypothesis. But this can easily lead to cherry picking data that appears to support your theory. And because you’ll be missing the fact that the same data also can be used to support other theories, or that other ideas also can produce the same evidence without your theory being correct. Only testing one’s own theory by looking for positive evidence, therefore, is a typical feature of pseudoscience.

Learn more about mastering the common biases in our thinking

Anecdotal Evidence and Testimony

There is also a tendency to rely upon anecdotal evidence and testimony. This is part of a more general feature of relying upon weaker forms of evidence, while eschewing stronger or more reliable forms of evidence. Now anecdotes are uncontrolled or ad hoc observations. They are not systematic. They are, therefore, plagued with confirmation bias and recall bias.

For example, if we are trying to assess the safety and effectiveness of a medical treatment, we can’t rely upon the testimonies of people or patients who have taken that treatment.

…if we are trying to assess the safety and effectiveness of a medical treatment, we can’t rely upon the testimonies of people or patients who have taken that treatment.

Let’s say, for example, we’re trying to decide whether or not a particular treatment helps to cure cancer and you may go to a meeting in which that treatment is being supported by anecdotes or testimonies of people who took the treatment and are now alive and doing well, maybe even cured from their cancer. However, those testimonies are being systematically biased. People who took the treatment and died are not there to tell their story. Dead men tell no tales, literally. Also, we don’t know that they didn’t take other treatments, variables were not controlled for them. Maybe they tried three or four or five different things, both standard and nonstandard treatments. How do we know which one is responsible for the fact that they are doing well?

Learn more about how pattern recognition is both a cognitive strength and a weakness

So, anecdotic is a pejorative term that scientists use to mean evidence which is uncontrolled, and therefore, plagued by biases, not systematic, subject to cherry picking, perhaps even systematically biased, and therefore, unreliable as evidence. But pseudoscientists will often heavily rely upon this evidence because essentially, they could make it say whatever they want it to say.

Image performing reiki on young woman at spa
Reiki is pseudoscience based which practitioners say is a universal life force, although there is no empirical evidence that such a life force exists. Clinical research has not shown Reiki to be effective as a medical treatment for any medical condition (Image: wavebreakmedia/Shutterstock)

There is this tendency to feel or to be more compelled by this kind of evidence. It takes critical thinking skills to understand that we shouldn’t really listen seriously to stories that other people tell us, at least not as confirmatory, definitive evidence. But people will often say things to the effect of, “Well, what are you going to believe, numbers on a paper or real people?” As if “real people” should be more compelling data. That kind of emotional appeal is also common among pseudoscientists who are trying to defend positions which the numbers on a piece of paper do not support.

Single Case Studies

Another feature to be wary of is the fact that core principles of a particular area of pseudoscience may be based upon a single case or observation, rather than a large body of carefully collected data. They use preliminary evidence, or even a single anecdote as a basis for then an elaborate later system of belief. They are essentially making the hasty generalization logical fallacy basing far reaching principles on a single piece of, perhaps, unreliable evidence.

Galileo Syndrome

Another feature that should send up a “red flag” that you might be dealing with the pseudoscientific end of the spectrum are grandiose claims based upon preliminary or flimsy evidence. We sometimes call this the “Galileo Syndrome” for the frequent tendency to compare oneself to Galileo. In other words, far reaching claims that overturn entire segments of well-established science are extrapolated from very little research or small bits of evidence.

This tends to occur with pseudoscientific endeavors because when theory conflicts with established science, rather than saying, “Hmm, there must therefore be something wrong with my theory,” or at the very least there is some anomaly that is not understood or I don’t understand. However, the pseudoscientist, rather, will simply broaden the implications of their own theory, claiming that, well, I guess all of this area of mainstream science must be wrong because it conflicts with my theory.

Learn more about skepticism in response to scientific claims and how blunders can be stopped

Pseudoscientists are also known for making very bold claims, claims that are not just bold, but often absolute. But the bottom line is that they go beyond the evidence. It’s okay to make big and grandiose claims, as long as you have the evidence to back it up, and even modest claims could be pseudoscientific if they extend too far beyond what the evidence can meaningfully support. Good science, rather, is very careful and conservative. It tends not to make claims which exceed the evidence.

For example, in the process of peer review, when experts in a field will review a paper submitted by one of their colleagues, in the hopes of being published. One of the specific things that they have to decide is do the conclusions of the researcher extend from the evidence? Can they be supported by the actual data that is being presented in the study? If the authors are making conclusions which are too bold, which go beyond the evidence, they will often be required to fix that before the paper can be accepted for publication.

Simple Answers

Another aspect of pseudoscience, I think related to the boldness and the extravagance of their claims, are that simple answers are often offered to very complex or multi-factorial problems. While scientific process often leads to simple or elegant solutions, pseudoscientists offer simplistic solutions even to very, very complex phenomenon. So, for example, we often call these a “theory of everything.”

Learn more about deconstructing several specific examples of pseudoscience 

Now, scientists are legitimately looking for more and more powerful and elegant theories that can explain more and more of the natural world, but when that process is taken to an extreme, and again leap frogs over the evidence, where one tiny, little phenomenon is used to explain our entire understanding of the universe, for example, then that becomes a theory of everything, a theory that is exceeding really the justification. In medicine, we often see this as the cause for all disease or the cure for all disease.

Hostile Reactions

Pseudoscientists also often demonstrate hostility towards scientific criticism. Science as we say is a harsh mistress. I spoke about the process of peer review, where a community of scientists is essentially highly critical of any new claims that are made. They will pick over data, make sure that their colleagues are counting through all the evidence, are not making claims which go beyond the data, are being critical and rigorous that they have gotten their math correct, all of these things.

Publication in a peer reviewed journal is a meat grinder, but it’s supposed to be. That is how science is supposed to work. That’s the only way to separate out those ideas that are useful and have potential from those that are a dead end.

Now, while no one likes to be criticized, scientists have to develop a thick skin because criticism is part and parcel of the process of science.

Pseudoscientists however, generally cannot accept this mainstream harsh criticism. They often do not engage with the scientific community. They claim that they are the victim of a conspiracy or a dedicated campaign against their ideas, perhaps because their ideas are simply too revolutionary. But these are all attempts to deflect the legitimate process of self-criticism that is supposed to drive science forward.

Learn more about experts and the nature of scientific consensus

Science Jargon

Science does tend to be a bit overwhelmed with what we call “jargon” and this can make it inaccessible or difficult to understand for the non-expert. But at its best, jargon is the use of terms that have very precise and unambiguous definitions. They are used so that experts can communicate to each other in an efficient and precise way without misunderstanding exactly what they’re talking about. This gives legitimate science this jargony feel that we all recognize, talking in technical, highly sophisticated terminology.

Pseudoscientists exploit this to use fancy jargony terms, but not to make their claims more specific, but to obfuscate, to hide what they’re really saying. They may use jargony terms that are vaguely defined or have a shifting meaning.

Failure to Progress

Pseudosciences are also marked by a failure to progress. Sciences that are legitimate and useful will tend to progress over time, whereas, pseudosciences tend to be stagnant. They are chasing their tail or they are endlessly trying to establish their basic principles of never moving off of even doing just that or as a very existence of the phenomenon that they are studying. They are still one hundred years later, for example, trying to establish that psi or ESP even exists, let alone progressing to define how it works and what are the other principles of ESP.

Anomaly Hunting

Anomaly hunting is another feature that is common to pseudosciences. Anomalies are very useful in science because they point to a shortage or a hole in our current understanding. They point to the way to new discoveries. However, looking for anomalies as a way of establishing a conclusion is what we call anomaly hunting. It does not seek to falsify or to explore alternatives, but just to say look, there is something unknown here. There is some anomaly, and of course, it’s easy. There are always anomalies to find if you look hard enough. Therefore, their view, their claim is true. So, the real fallacy they’re committing is in using anomalies to prove or confirm a conclusion, rather than just as a starting point for later investigation.

Common Questions About Pseudoscience

Q: How can we tell the difference between pseudoscience and science?

We can easily discern pseudoscience from science as the former is careless, results cannot usually be reproduced, the study does not rely on empirical evidence but rather appeals to emotion, and practitioners generally refuse or buckle under peer review.

Q: What exactly is pseudoscience built on?

Pseudoscience is composed of beliefs and theories that are not based on scientific literacy and have not been organized with thorough, empirical facts and evidence but rather stories, feelings and shifting data.

Q: Is the Flat Earth theory pseudoscience?

Yes. The Flat Earth theory is easily debunked as pseudoscience as it attempts to use some basic scientific concepts to describe a lack of curvature of the Earth, ignoring the fact that we have mathematical descriptions of the curvature which are used heavily and to accurate effect by industries including military, naval, snipers, and large-scale construction.

Q: Does Astrology fall under the category of pseudoscience?

Astrology is considered a pseudoscience. While it was useful to know of the rotation of the zodiac for navigation or agriculture, there is no modern use of the zodiac with empirical evidence that shows how the shapes of stars in the night sky influence our daily life.

This article was updated on 9/27/2019

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