Distinguishing pseudoscience from science

by Azilleo Kristo Mozihim

We are constantly bombarded by all sorts of claims presented through the mass media purported to be scientific. However, many of these claims failed to pass rigorous scientific testings and are termed “pseudoscientific claims”. While by no means definite, pseudoscientific claims can be distinguished from scientific ones based on three criteria – falsifiability, scientific plausibility and communication among experts of the field. By using these three criteria, it is hoped that we can pick out genuine scientific claims from dubious pseudoscientific ones as we are incessantly bombarded by endless number of claims in today’s modern world.

Have you ever wondered about your Zodiac sign? You are likely to have stumbled upon the horoscope section of a newspaper with the 12 Zodiac signs along with their respective daily fortunes.  You might read these and be pleasantly surprised that the events described match those you have encountered. For many of us, such coincidental matches are hardly evidence for the legitimacy of our Zodiac fortunes. In fact, such disbelief in Zodiac signs and their fortunes is probably due to them being part of what is popularly known as Astrology – an ancient practice of divination based on the characteristics of celestial bodies.

Astrology, along with several other practices such as Homeopathy and Palmistry, are considered pseudoscientific – practices or beliefs that lack qualities required for them to be deemed ‘scientific’. Recognising pseudoscience from genuine science is pivotal considering that many claims mushrooming in mass media are based on pseudoscience instead of genuine science. With that being said, how does one distinguish pseudoscience from genuine science? This question has been grappled with by many of the illustrious philosophers of science of the past such as Karl Popper and Thomas Kuhn. However, even among them and modern philosophers of science, there is currently no consensus. Despite that, several criteria can be used to weed out claims that have a pseudoscientific bent from those that are backed up by extensive scientific research. We shall use several notorious pseudoscientific practices along with their scientific counterparts to illustrate these concepts.


Consider these two statements: ‘Your zodiac totem of the two fishes signifies that you are unsettled, variable and unlikely to focus and settle on a decision’ and ‘The square of the period of any planet is proportional to the cube of the semi-major axis of its orbit’. The former is a Pisces fortune obtained from an astrology website while the latter is Kepler’s Law of Period, a well-known law in Astronomy. These two statements demonstrate the first main difference between pseudoscience and genuine science: falsifiability. In simple terms, falsifiability means that it is possible to devise a specific test to determine whether a particular statement is true or false. For this to be possible, the statement has to be phrased using clear and unambiguous terms. The Pisces fortune is couched in imprecise terms such as ‘unsettled’ and ‘variable’: it is unclear how the state of being ‘unsettled’ and ‘variable’ are to be defined or objectively determined within the context of the fortune. With such imprecise terms, it is difficult, if not impossible, to determine a test that can falsify the statement. In contrast, Kepler’s Law is stated clearly and unambiguously: ‘period’, ‘orbit’ and ‘semi-major axis’ are terms that have specific definitions, agreed upon by the scientific community. Furthermore, the law states a relationship between the concepts in such a way that a test can be devised to possibly falsify it: the period of various planets along with the semi-major axis of their orbits can be objectively measured with various scientific tools and if the square of the period is not found to be proportional to the cube of the semi-major axis of their respective orbit, Kepler’s Law is falsified. While falsifiability is not the sole distinguishing criterion, it does determine whether a claim is possibly scientific; a scientific claim must be determined to be either true or false but if a claim is unfalsifiable, whether it is true or false cannot be ascertained.

Scientific Plausibility

Pseudoscientific claims usually conflict with our current scientific understanding of the physical world; that is, they are scientifically implausible. For instance, the practice of homeopathy is grounded on the idea that water has the ability (so-called water memory), to retain some imprints of the substances previously dissolved in it even after numerous rounds of successive dilutions. This notion conflicts with our fundamental understanding of science which precludes the existence of such a property in water. Another example of such conflict is demonstrated by the underlying belief of astrology: the positions and timing of celestial bodies such as the planets, Sun and moon can affect the life trajectory of human beings. Again, this belief flies in the face of our current scientific understanding as there is no known physical mechanism through which the celestial bodies can directly affect the destiny of human beings at such great distances. By contrast, there are claims which are scientifically sound and evidence-based; for instance, the claim that vaccination can significantly reduce the risk of contracting certain infectious diseases is based on our scientific understanding of the human immune system, natural immunity and the infectious agents. In addition, it is also supported by numerous animal studies and clinical trials designed to rigorously test its effectiveness. While pseudoscientific claims are generally scientifically implausible, it should be borne in mind that it does not necessarily imply that they are absolutely untrue as this depends on our current scientific understanding. Thus, it is still possible for current pseudoscientific claims to become scientific in light of new discovery. Even so, it is a safe bet to take a claim with a pinch of salt if it requires the revision of almost all of our scientific understanding for it to be true.

Communication Among Experts

A claim also needs another important factor in determining its scientific status: communication among practitioners of the field with which it is usually associated. Practitioners of fields fraught with pseudoscientific claims rarely communicate in a way that allows them to compare their findings and ideas with each other. Without such communication, there will be little opportunity to discuss, argue or criticise any claims and findings that are made in relation to their field. This allows unsubstantial claims to be masqueraded as ‘true’ despite not having been subjected to critical evaluation by them. Practitioners of Astrology, for example, do not have a communication platform on which they communicate their ideas and findings. If let say that they have an idea about a particular new method or a new astrological concept, it is rarely evaluated by other astrology practitioners and can be presented as ‘true’ despite not being previously critically scrutinised. On the other hand, practitioners of science – such as biologists, physicists, chemists, astronomers and geologists – have several of such communication platforms. They present their findings or ideas in the form of written publications in scientific journals after they have been rigorously reviewed by peers and editors and also as oral presentations or posters at scientific conferences. Through these various means of communication, the ideas and findings of scientist will be subjected to repeated attempts of critical evaluation by fellow practitioners before they are considered ‘acceptable’ based on the standards of the field. These publications and scientific proceedings contribute heavily to the assessment, career progression and research funding success of a scientist. Such critical evaluation and communication are patently absent among the practitioners of pseudoscience, leading to unsubstantiated claims to unduly propagate.

Falsifiability, scientific plausibility and communication among experts – these are the three criteria that can help distinguish pseudoscientific claims from scientific claims. As discussed, these criteria can be assessed to roughly determine whether or not a particular claim you encounter is pseudoscientific. Although that may be the case, it should be noted that there are many other criteria that could be necessary to more reliably determine the pseudoscientific nature of a claim; for example, the track record of the field of the claim in solving problems, the usage of logical fallacy, the tentativeness of the claim made by the practitioners etc. As stated in the beginning, there is no list of criteria agreed upon by experts that conclusively determine whether something is scientific or not and this lack of consensus is called the demarcation problem, a problem that has serious practical ramifications, particularly for laymen that trust in the authority of science. Even so, using the three criteria elaborated in this article can help guard against being deceived by pseudoscientific claims masquerading as legitimately scientific in mass media.

“Did you know?”

The word ‘science’ comes from the Latin scientia, meaning “knowledge, a knowing; expertness.” In modern usage “science” most often refers to a way of pursuing knowledge, not only the knowledge itself. [Wikipedia]

Source: https://en.wikipedia.org/wiki/Scientific_method

About the Author

Azilleo Kristo Mozihim enjoys being in the lab conducting research on biological systems at a molecular level. While passionate about science, he enjoys widening his intellectual horizons by reading scholarly works of various disciplines, particularly Philosophy and Economics. Besides academics, he spends his free time cooking various dishes but mostly chicken dishes and he especially takes delight in eating Hainanese chicken rice, whether personally made or ordered in a restaurant. He hopes to pursue his PhD after his undergraduate, planning ultimately to become professor who is active in teaching, research and public service. Find out more about Azilleo by visiting his Scientific Malaysian profile at http://www.scientificmalaysian.com/members/azilleo/

This article first appeared in the Scientific Malaysian Magazine Issue 11. Check out other articles in Issue 11 by downloading the PDF version for free here: Scientific Malaysian Magazine Issue 11 (PDF version)


[1] “Evidence Check 2: Homeopathy – Science and Technology Committee.” Retrieved 24/06, 2015, from http://goo.gl/Z0jDPP

[2] “Kepler’s Law.” Retrieved 26/06, 2015, from http://goo.gl/6asb1G

[3] “Pisces Career and Finance.” Retrieved 25/06, 2015, from http://goo.gl/k2VcWy

[4] Ruse, M. (2013). Creation -Science Is Not Science. Philosophy of Science. M. Curd, J. A. Cover and C. Pincock, W.W Norton & Company: 20-26.

[5] Thagard, P. (2013). Why Astrology Is A Pseudoscience. Philosophy of Science. M. Curd, J. A. Cover and C. Pincock, W.W Norton & Company: 27-36

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