Most people I have ever talked to have, at least, a passing interest in psychology, and human behavior. And us all being human, we have some personal experience which would lead us to feel that we are experts on the matter. With so many resources available to help the layperson with science it feels like anyone could be an expert.
With how easy it is to consume science though, it gets easier to confuse pseudoscience for real science. What is pseudoscience? Merriam Webster defines it as “a system of theories, assumptions, and methods erroneously regarded as scientific.” Since one can pretty easily assume that pseudoscience is, in fact, not science, this definition is a little less than helpful. Luckily there is one place we can turn to figure out how to differentiate between science and pseudoscience.
“Karl Popper is generally regarded as one of the greatest philosophers of science of the 20th century.” While working under Alfred Adler, a prominent psychologist who believed people acted out of an “inferiority complex”, Popper saw a problem in the theory. He used the story of a person drowning a baby, and another person coming to save it to make his point. According to Adler, both people are acting because of their inferiority complex. The first person needed to show that he “dared” to drown the baby, and the second needed to show he “dared” to save it.
He concluded that every human behavior could be explained in light of this theory, and because of that there is no way to test it. He compared Adler’s theory to Einstein's theory of relativity where experiments could have concluded Einstein was wrong, with Adler you can explain anything with his theory, just like you can explain all human behavior by saying that invisible ghosts are doing it.
Popper gave us some helpful rules to look at when distinguishing from science and pseudoscience:
“(1) It is easy to obtain confirmations, or verifications, for nearly every theory-if we look for confirmations.
(2) Confirmations should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory-an event which would have refuted the theory.
(3) Every "good" scientific theory is a prohibition: it forbids certain things to happen. The more a theory forbids, the better it is.
(4) A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of theory (as people often think) but a vice.
(5) Every genuine test of a theory is an attempt to falsify it or to refute it. Testability is falsifiability, but there are degrees of testability; some theories are more testable, more exposed to refutation, than others; they take, as it were, greater risks.
(6) Confirming evidence should not count except when it is the result of a genuine test of the theory; this means that it can be presented as a serious but unsuccessful attempt to falsify the theory. (I now speak in such cases of"corroborating evidence.")
(7) Some genuinely testable theories, when found to be false, are still upheld by their admirers-for example by introducing ad hoc some auxiliary assumption, or by re-interpreting theory ad hoc in such a way that it escapes refutation. Such a procedure is always possible, but it rescues the theory from refutation only at the price of destroying or at least lowering its scientific status. (I later described such a rescuing operation as a "conventionalist twist" or a "conventionalist stratagem. ")
One can sum up all this by saying that the criterion of the scientific status of a theory is its falsifiability, or refutability, or testability.”
In conclusion, to tell pseudoscience from science you can’t look at what a theory explains, but by knowing what it predicts cannot happen.