Psychology wields a fair amount of power in our society - criminals are sentenced or released based on the evidence of psychologists. Employers often rely on psychological tests to determine whether you get the job or not.

As a scientific realist, this is concerning to me. I need to know whether psychology (especially cognitive psychology) is a method for determining facts about the world. And if it fails the scientific bar - should we not treat its results and recommendations with more skepticism?

The biggest argument I've heard in favour of considering cogntive psychology a good scientific field is that it relies heavily upon the scientific method for many of its results. Fair enough, but one can argue that you can apply the scientific method to the study of Star Trek - that surely does not make "Star Trek"-ology a valid scientific field. For something to be a science, you do not just need to use the scientific method (the semantic commitment of scientific realism) - the object under scrutiny needs to be a fact of the world too (the metaphysical commitment of scientific realism). And, as far as I'm aware, those results need to be generalised into a set of laws that provides predictive power.

Here are some of the arguments I've heard that disputes the scientific validity of psychology:

  • Lack of predictive laws. I read somewhere that psychologists perform no better than chance to predict which criminals would re-offend upon release, even with good access to the individuals (*). Should scientific theories not result in falsifiable predictions? What is the use of knowledge if it does not aid us in prediction?
  • Results in neuroscience are casting doubt on psychological assumptions about the reality of mental states and whether our brains work in terms of propositions. (**) If the mind is the brain, and the brain works fundamentally different from how psychologists claim the mind works, does that not provide a good reason to doubt the claims of psychology?
  • Secretive practices. For example, the test for psychopathy is a secret test that is only available to registered psychologists (*). Even though this may be for good reason (to prevent psychopaths from cheating the test, I imagine), this does cast doubt upon the field's ability to provide objective measurements that are both indisputable and open to scrutiny. Even worse, this is a slippery slope to creating a "cult of authority" where it becomes difficult to argue against psychological diagnoses.
  • Doubt about the efficacy of psychological treatments like talk therapy for common mental ailments such as alcoholism, depression and bi-polar disorder. It is now well-known that treating these mental disorders in the terms of the propositional language once favoured by psychologists are largely ineffective and have been replaced by psychiatric and neurological treatments.

As a scientific realist, it seems to me that psychology must fall into one of the following categories:

  1. A reliable method for establishing facts about the human mind. With further research and study, the methods will improve and the predictive laws will come.
  2. A useful fiction (like a Dennetian stance), that may not be grounded in physical reality but still provide us with enough useful practices and methods to improve our lives.
  3. A radically wrong discipline (like alchemy or homeopathy) that may on occasion stumble upon a "useful trick" but is never going to provide us with reliable knowledge about the human mind and its role in nature.
  4. Complete uncritical bunk.

I may be committing the fallacy of excluding possibilities here, but because of the arguments outlined above, I'm almost certain that there is something wrong with 1).

I suspect we generally assume that 2) is where psychology is at, but I wonder how sure we are about it. What research have been done to show the efficacy of psychological treatment of patients vs other forms (like psychiatric, neurological and even no treatments?). What are the standards of the psychological community in accepting a treatment as more than mere placebo? Do we have good reason to believe that psychology provides insights into the mind that are superior to other known methods?

3) and 4) provide me with the greatest concern - how certain are we that we are not just entertaining a deluded society and yielding a disproportionate amount of power to them?


(*) It is either "In Cognito: The secret lives of the brain" or "The Self Illusion: Why there is no you inside your head". Sorry for not being very specific.

(**) This view seems to be the basis of eliminative materialism, with the Churchlands being good examples of proponents.

(*) Without Conscience: The Disturbing World of the Psychopaths Among Us

  • I agree with you that "scientific psychology" is hardly a science at all ... but the "art" of managing a complex society requires tools which "hard scinces" are not able to provide yet. Jun 3, 2014 at 9:14
  • Sure, but is that not the problem? We only figured out that alchemy was bunk when we discovered chemistry. We only know homeopathy is bunk because we have medical science. Is it not possible that we will one day know that psychology is bunk when we discover x (with x being a theory of mind that provides predictive laws?) Is the lack of a predictive theory of mind an excuse to accept a wrong one?
    – firtydank
    Jun 3, 2014 at 9:40
  • What I'm saying (it is quite trivial) is that I agree with you that quantum mech is much more "scientific" than psychology, but social sciences in general offer "tools" which (imperfect as you want) are much more "usuful" to social management then quantum mech ... Jun 3, 2014 at 13:56
  • @Mauro - Yes, I think I got that. My question is whether they are indeed more useful, and how do we know? Keep in mind that we sometimes send people to prison (or keep them out of prison) based on the opinions of these experts.
    – firtydank
    Jun 3, 2014 at 14:24

5 Answers 5


I am currently pursuing my PhD in clinical psychology, so perhaps I can shed some useful light here. Psychology is a huge, sprawling discipline that covers almost everything in some way or another. It is also a very young discipline in a rapidly developing world.

This means that some of psychology is science through and through, and that some of psychology is decidedly not scientific.

There is actually a war within psychology right now about two largely used different models of education and clinical practice. These are the scientist-practitioner and the practitioner-scholar. (http://en.wikipedia.org/wiki/Practitioner%E2%80%93scholar_model http://en.wikipedia.org/wiki/Scientist-practitioner_model).

Psychology has so many sub-disciplines and goals that are so vast reaching and pursed in different ways that generalizing "science or not science" to the entire field is pointless.

I will say that the scientist based practices and areas are growing. Universities that teach the scientist-practitioner model are the ones producing researchers who follow the scientific method and who get information as reliable and real as any other scientific discipline when they are also following the scientific method. (I will note here that there is disagreement about the scientific method within all sciences, but that that is not the question here).

As vague as 'cognitive psychologist' is in practice, I will say that cognitive/developmental psychology is one of the oldest and most widely practiced sciences within psychology. Bandura is one of the founders of cognitive psychology and he was following the work of Watson, Skinner and Pavlov. Besides the historical look, there are things we know in psychology because of science. For instance, Dialectical Behavior Therapy has been shown to be a well established (http://www.apa.org/divisions/div12/est/newrpt.pdf) treatment for Borderline Personality Disorder.

I'm sorry to be so vague but I would say that particular practices within the feild fall into every category you've listed. Most of our research falls under 1). But I am fully aware of a lot of pseudo-psychology or pop psychology that falls into 3), such as Freudian theory.

I am happy to answer any more specific questions. Hope this was helpful.

  • Thanks Alysse, that is very helpful! I accept that psychology is a huge field and perhaps it is folly to attempt any kind of generic judgments about it. Still, there is a perception (at least to me) that psychological study have failed to provide cohesive scientific theories about the mind. Although I do not dispute that interesting and verifiable results have been obtained using the scientific method, the scientific realist (and scientists in general) puts a high price on cohesion - that is that results in one discipline feeds into, enhances and illuminate results in other related fields.
    – firtydank
    Jun 5, 2014 at 15:33
  • So my question really is: is this perception justified? Kant once remarked that there is no "Newton of the blade of grass", meaning that he believed biological study would never be subject to this kind of multi-disciplinary cohesion provided by good scientific theories. Darwin proved him wrong of course. But where is the "Newton of the mind"?
    – firtydank
    Jun 5, 2014 at 15:36

Let's distinguish between cognitive psychology, which I will argue is absolutely a science, and cognitive-behavioral psychotherapy, about which I do not have an informed opinion.

Cognitive psychology as it is often defined (for example on Wikipedia) is the study of how brains process information. Cognitive psychologists produce testable, falsifiable, and measurable theories about how natural information processing works and then construct experiments or collect data to test their theories.

One of the most famous papers in cognitive psychology is George A Miller's, "The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information", Psychological Review, 63(2):81–97, 1956. doi:10.1037/h0043158 asserted that the number of "chunks" of information that can be stored in the human short-term memory is "about" seven. The paper itself reports several experiments, and multiple experiments since then have examined the assertion in other contexts.

A second example often included in cognitive psychology is linguistic research into the grammar of human languages. In 1957 Chomsky asserted that the grammars of all human languages share a set of characteristics, and he began to examine the information processing limits of various different kinds of processes with respect to those characteristics. He showed that Markov chains, for example, are insufficient to differentiate correctly between grammatical and non-grammatical sentences, while pushdown automata do seem to be able to differentiate between grammatical and non-grammatical sentences in almost every natural human language. (This class of languages is now called "context free languages.") This is a theory which could be falsified by studying all existing and past human languages and trying to find one where the grammar was either simple enough to be described with a finite automaton, or finding one that is too complex to describe with a pushdown automaton.

Not that I think any of that has any bearing on criminal trials.

  • Thanks WL, a very informative answer indeed. But here is my problem - scientific theories have a certain cohesion (which is why scientific realists believe them to be true). For example, our model of elementary particles makes predictions in a wide variety of scientific fields like QM, chemistry, biochemistry, astronomy, geology etc etc. This means that this theory is tested and verified in a multi-disciplinary society...
    – firtydank
    Jun 4, 2014 at 7:09
  • The theories of cognitive psychology on the other hand seem to be ... "local" for lack of a better word. It seems that cp's make an observation, postulate a theory, make some predictions and test them. All very well, but it still seems to be missing that cohesion - that underlying theory of how it all fits into the bigger picture seems to be missing. Has Chomsky's language results made predictions on theories about memory capacity or attention span? The CP community seems to me to be very much a large number of islands doing work that involves mental processes without this important cohesion.
    – firtydank
    Jun 4, 2014 at 7:15
  • Imagine we have a black magic ball that produce interesting but largely unexplained behaviours, like lighting up in green or bouncing around. Sure, over time we may be getting predictable results using the scientific method (if I touch the ball here then a green light goes on there), but since we have no idea what is going on inside, until these theories become cohesive (the same theory that explains the green light also explains the bounce), we should assume them to be radically wrong or at least incomplete (from a scientific realist point of view). This is where cp is at, I argue.
    – firtydank
    Jun 4, 2014 at 7:24
  • Your magic ball analogy better fits the decidedly non-realist school of behaviorism, which cog-sci largely repudiated. Cog-sci posits that there is no magic, and tries to discover the physical mechanism that determines the ball's behavior. Jun 4, 2014 at 12:11
  • 1
    But to be frank, I suspect we have a difference in definition and vocabulary that is preventing us from discussing this issue constructively, even if we may actually agree on many points (which I suspect).
    – firtydank
    Jun 5, 2014 at 11:52

This seems to be a clash of two different views on epistemology.

As a scientific realist, this is concerning to me. I need to know whether psychology (especially cognitive psychology) is a method for determining facts about the world. And if it fails the scientific bar - should we not treat its results and recommendations with more skepticism? It may more about discovering facts about behavior and how humans interact with each other. It may not be inclined to uncovering facts about the world. What exactly doe failing the scientific bar mean? Is a pursuit only worthy of pursuing if it is scientific in nature?

Science has meant different things in different times. If you asked what the question was in Medieval times you would get an answer that would include Theology. If I'm to assume that you mean natural science as is the usual definition in this era then yes Psychology is not a science by that definition.

With that being true anything that is not natural science does not meet that criteria but are still very much worthy of pursuit. Surely whether a pursuit succumbs to some sort of arbitrary definition of science has very little to do with whether its truth claims have bearing or whether it is a good field of study.

To think that if you can prove something pseudo science or soft science then you have proven that is unworthy of study is nothing more than intellectual vanity or discipline chauvinism.

  • Whether psychology is worthy of study is neither here nor there for me - my concern is about the amount of influence we yield to a discipline which may not have the credentials to justify it.
    – firtydank
    Jun 3, 2014 at 9:32

The brain is notoriously complex, I would look to parallels elsewhere.

Consider the plum-pudding (or, as I learned it, the "blueberry muffin") model of the atom. This was discredited as being wrong after only a few years. But, it was useful - it was the first model to reconcile an "atom" (the very word meaning "indivisible") as having different parts.

The parallel here is that psychology is a field that provides us with models. Some of these models are useful, but not all of them are (just as not all models to come out of physics or economics are useful). Of course, there is only a fine line between what you call "a useful fiction" and a model.

Instead of looking at psychology as a whole, I would look at individual results from psychology. Those that have been disproved can be thrown out. Results based on poorly done studies, or studies that misuse statistics, or studies that cannot be replicated can be ignored.

It seems that psychologists (or, at least some of them) are aware of the point you raise. Looking at a piece by Andrew Gelman and the links coming off of the piece describe many of these problems with how psychologists evaluate their hypotheses. If you buy this analysis, it seems that in psychology scientific best practices are not often followed. In such case, it should not be surprising when results are not valid.

There is another, different problem of psychology which results in untestable hypotheses. It seems that the best one can do with such work is to try to digest it into testable hypotheses.

  • The way we discard models in science is by testing their falsifiable predictions - psychology does not seem to provide many of these. By what criteria do we go about accepting a result in such a case?
    – firtydank
    Jun 3, 2014 at 14:21
  • Edited answer - there are two separate problems: work that doesn't yield falsifiable hypotheses, and falsifiable hypotheses that are incorrectly evaluated. Jun 3, 2014 at 16:26

I have a few things to say about your question. I think the question itself is problematic because it depends on a bad understanding of realism and this has pointed you in the wrong direction.

The first interesting thing about your question is that you are a realist and one question you ought to ask is why you hold that position. I am not saying you are wrong, you are right, but the explanation for why you're right is more complicated than most people admit and it is relevant to this issue. You think the world exists independently of what you see and measure about it. This idea is not experimentally testable. Consider the alternative that the world only exists when you are looking at it or measuring but the measurements you do make have the same results as they would if the world did exist while you're not looking at it. This idea can't be distinguished experimentally from realism. It can only be eliminated from consideration because it is a bad explanation. It consists of taking the world as described by realism and sticking arbitrary labels on some parts of the world saying they're not real. It also relies on a naive notion that measurement just involves looking at the world and so can be cleanly separated from the rest of our explanations. But this is false. Observations require a lot of careful thought about how your experimental apparatus works and that sort of thing. The way to decide between competing idea is whether the explanation they give for how the world works is consistent with other ideas, including the results of experiments, but not limited to the results of experiments. (See "The Fabric of Reality" and "The Beginning of Infinity" by David Deutsch and "Realism and the Aim of Science" by Karl Popper for the best available philosophy of science.)

You say that the Churchlands advocate eliminative materialism: the idea that beliefs, feelings and that sort of thing will be eliminated by a scientific understanding of humans. Beliefs are just abstractions: they are patterns that can be instantiated in any physical system that obeys certain restrictions, e.g. - it can retain the same state over time, the state can easily be read out and error corrected and that sort of thing. So if we're going to eliminate beliefs then the theory of computation has to be eliminated too, since it is about how abstractions can be instantiated in physical objects and it applies in the same way to the brain as to any other object. But that theory has explanations that can't be expressed in terms of the laws of motion of atoms and that sort of thing, but are needed to solve many problems.

You note that psychologists are not very good at predicting behaviour. There is a reason for this. A person's behaviour depends on what knowledge he has. He gets that knowledge from interacting with other people, from culture (television, books and so on) and creating new knowledge. The growth of knowledge is not predictable because if we could predict what we will know tomorrow we would already know it. Since it is impossible to predict what ideas he might come across and his behaviour is dependent on those ideas, his behaviour is not predictable. For the same reason, I don't think psychiatrists can predict or control a person's behaviour, their pretensions to the contrary notwithstanding.

You ask what the standards are for assessing psychological and psychiatric treatments. The claim behind these treatments is that some behaviour is caused by illnesses or syndromes. This discards as unworkable the idea that a person has adopted some position or behaviour to solve a problem he finds pressing, which is how people really do make decisions. What sort of behaviours are treated as illnesses or syndromes or whatever? Behaviours that are problematic for somebody. An alcoholic's behaviour may be problematic for himself or his spouse. A child diagnosed with ADHD behaves in a way that parents and teachers find problematic. but if this behaviour is problematic why does the person keep doing it? Because nobody has offered him an alternative he considers better. What is going on is a disagreement over how a person ought to behave: a moral disagreement. To attribute this to brain illness makes about as much sense as thinking there is something wrong with the electronics in your television if you see a program you find distasteful. Instead of openly admitting there is a disagreement people prefer to take the position that the person with whom they disagree is ill. If you are not going to treat a person's behaviour as motivated by some problem and argue with them admitting that you might have to change your mind, what's left? You heave to either separate from the person or get him to submit to you by making his life difficult if he doesn't submit. A large part of psychiatry involves making a person's life difficult until he stops exhibiting the behaviour others don't like. That is the standard by which psychological and psychiatric treatments are judged. You might want to read "The Medicalization of Everyday Life" by Thomas Szasz to understand more and www.szasz.com.

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