This article first appeared in Issue 15 of our free digital magazine CURIOUS. 

We exist in an increasingly online world that bombards us with information at every opportunity. A simple scroll on our favorite websites, news outlets, and social media platforms can bring a torrent of (sometimes questionable) content down on our heads, and it can be a nightmare to decipher the fact from the fiction – especially when it comes to science.

It’s no wonder, therefore, that we find ourselves asking more and more often: Is this science or is it snake oil? And, more importantly, how can we tell?

This distinction, also known as the demarcation problem, is “key to most of the fundamental problems in the philosophy of science,” according to Karl Popper, one of the 20^th century's most influential philosophers.

Despite its importance, it’s not always easy to know what’s science and what’s not. Fortunately, there are some tell-tale signs that may help in navigating the maze of misinformation out there – here’s how to spot a pseudoscience in the wild.

Pseudoscience: a history

Pseudoscience is a system of thought or a theory that is erroneously regarded as scientific despite not being rooted in science. Pseudoscientific ideas predate the scientific era, and in some cases are ancient – the practice of astrology can be traced back to the 3^rd millennium BCE, for example.

Things really got going in the 19^th century, which saw a burgeoning of pseudoscientific ideas. Practices such as phrenology – the idea that bumps on the skull can reveal aspects of our personalities – spirituality, and telepathy became popular, and proponents of them often published their beliefs in books and magazines, presented as "research".

The dawn of the Space Age in 1957 saw things take an extraterrestrial turn, with ancient astronaut theories taking off. However, by the end of the 20^th century, skepticism had begun to grow and various societies aiming to counter pseudoscience popped up, including the Center for Inquiry (1991) and Skeptics Society (1992).

Famous examples

Today, belief in pseudoscientific theories is still rife – you only need spend five minutes on TikTok for evidence of that.

Popular examples include the previously mentioned astrology – the concept that the movements of celestial bodies somehow influence our daily lives – which has reams of fans despite evidence it isn’t real; numerology – the belief that the numerical values of our birth and name can reveal deep truths about us; and the handwriting-based personality practice called graphology.

You might also be familiar with homeopathy, cryptozoology (seriously, where is Nessie?), pseudoarchaeology (looking at you, Atlantis), acupuncture, and aromatherapy, which are all largely considered to be pseudoscience. And that’s naming just a few.

But what separates these ideas apart from legitimate science?

Science vs. pseudoscience

A quick Google will tell you that science is “the systematic study of the structure and behaviour of the physical and natural world through observation, experimentation, and the testing of theories against the evidence obtained” – which is a lot of words to essentially say that science adheres to the scientific method.

This begins with a question, which is developed into a hypothesis and tested in a series of experiments, the results of which can be used to draw new conclusions. Ultimately, the process enables us to generate knowledge, make predictions, and advance our understanding.

A pseudoscience, on the other hand, may present itself as scientific, but is in fact incompatible with this method. It often starts with a conclusion and works backwards to find the evidence to “prove” it.

Even with these intrinsic differences, it’s not always clear where pseudoscience ends and science begins: alchemy paved the way for the science of chemistry, after all.

A crucial tenet of “science” is that it builds on previous knowledge, using what has come before, alongside new evidence, to support or refute a theory. Because of this, it is highly adaptable and can change in light of new information.

For example, a widely accepted scientific theory, like Einstein’s relativity, may be the best current explanation that we have for something, but only until a better one comes along.

“Anything that is truly scientific is going to allow for that kind of refinement and even that kind of rejection,” Rachel Ankeny, a professor of philosophy of science at the University of Adelaide, told IFLScience.

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However, pseudoscience, which has likely not been subjected to such scrutiny and stringent testing, tends to be much less malleable. 

“For something to be a scientific fact, typically, they have to be a finding that has resulted from careful attention to building empirical evidence. [...] In different fields, these are going to be different but it often involves observations, testing, and measuring through experimentations,” Ankeny added. 

The same cannot be said of pseudoscience, which instead of repeatedly carrying out rigorous testing relies on claims of “ancient methods” used for “thousands of years” or cherry-picks its evidence from real existing data, sometimes just one small study, not widely evaluating any further or updated findings and often taking those findings out of context to fit a foregone conclusion.

Even with these intrinsic differences, it’s not always clear where pseudoscience ends and science begins. And sometimes it can seem like the fields themselves are confused: the pseudoscience of alchemy paved the way for the science of chemistry, after all.

So how can you work out what to take seriously when the waters are so diluted? (Yes, that was a homeopathy joke.)

How to spot a pseudoscience

Gwyneth Paltrow’s Goop, which sells many unscientific “wellness” items, from healing crystals to energy rebalancing stickers, has an estimated annual revenue of $18-60 million.

The first thing to ask yourself is “Where has this come from?”. Experts are experts for a reason, and if they’re touting something then it’s likely to be more valid than if, say, you heard it from your mom’s friend’s neighbor. Always question a big claim’s sources.

The next thing you might want to consider is “Why?”; what is the purpose of this theory, and what could someone gain from it? Science generally strives for discoveries to open up new avenues of research, advance knowledge, and perhaps influence current policies or worldviews. Its purpose tends to be more altruistic than pseudoscience, which may be pushing an agenda – perhaps someone stands to benefit financially or in some other way by pushing this idea. Gwyneth Paltrow’s Goop, for example, which sells many unscientific “wellness” items, from healing crystals to energy rebalancing stickers, has an estimated annual revenue of between $18-60 million.

If in doubt, you can always turn to The Research. As we’ve established, science is supported by a broad body of evidence that has stood up to peer review and the scrutiny of scientific peers. Robust evidence is more likely to suggest something is science, whereas limited, flimsy, or cherry-picked data hints otherwise.

If we’re talking science, this evidence is likely to have changed over time, so you should look out for an evolution of ideas. If the principles are more or less unchanged since a concept was first introduced, or no new research has been conducted, you could have a pseudoscience on your hands.

In a similar vein, you could consider how a theory responds to challenges. If it, or its supporters, ignore or refuse to accept contradictory evidence, it may not be legitimate. Science, on the other hand, embraces challenges.

Last but not least, let’s return to our old friend Karl Popper. His theory of falsification posits that for a theory to be considered scientific, it must be able to be tested and conceivably proven false. However, many pseudoscientific claims cannot be tested and so cannot be proven or, crucially, disproven. Where pseudoscience shies away from falsification, science seeks it, something that can be useful to contemplate when looking to uncover a pseudoscience.

Armed with these top tips, you can not only satisfy your skepticism but, according to Popper, you can solve most of the problems in the philosophy of science. We bet that wasn’t in your horoscope for today.

CURIOUS magazine is a digital magazine from IFLScience featuring interviews, experts, deep dives, fun facts, news, book excerpts, and much more. Issue 18 is out now.