Is Psychology a Science?

Is Psychology a Science?Over the past year, psychology as a field, and in particular social psychology, has come under scrutiny after several notable cases of scientific fraud. The most notable was Diederik Stapel, who outright fabricated data for at least 30 publications. A couple other cases of data manipulation and fraud have just surfaced recently, leading to further resignations of researchers in the field. Amidst these news stories, some have asked the question, “Is psychology trustworthy? Is it even a science at all?”

Of course, these are not new questions for psychology to deal with. Making the case for psychology as a science has been a continual process over the years, and psychology to some extent still suffers from the impression that has remained from the psychoanalytic tradition of Freud. The psychoanalysts loved to sit people on couches and talk about dreams and repressed childhood memories and so on. But we’re past Freud. Honest.

However, given the recent scrutiny, I thought it appropriate to take the time to address the question again and argue that yes, psychology is indeed a science. I come from the perspective of a graduate student in social psychology—traditionally the most “suspect” of the areas in psychology—and as such, most of my experience and examples come from that area. I approach this question from the “if it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck” approach (see, I’m using the scientific method already!). I would like to argue that psychology operates very similarly to other fields of science that are not in dispute—the so-called “hard sciences”. So let me outline just a few of the ways in which psychology parallels these fields.

1. Psychology makes observations that lead to numeric data that can be analyzed statistically.

Dealing with the human mind is a difficult subject. It’s complex (the most complex thing in the universe that we’ve ever discovered), it’s situated in a complex system of social and cultural forces, and its hardware, the brain, is a complex organ that we are still trying to understand. As such, with all the complexity involved, one might expect psychologists to throw up their hands and resign themselves to leaving the human mind a mystery. But despite this, they have come up with methods for making observations that lead to quantifiable data that can be analyzed using established statistical methods. Much of these data are observed through actual behaviour of participants: How far away does the White person sit from the Black person? How long do they spend working on this task? How many cookies vs. veggies do they eat? These behaviours can provide inferences into people’s motivations (e.g., prejudice, persistence, dieting) as well as the thought networks that exist in their heads. Psychologists also use lots of self-report surveys asking people questions about what they think or feel about things. They are, of course, well aware of the drawbacks to self-report. Psychologists are the ones who discovered the biases people have when reporting their own attitudes and beliefs, after all! That’s why psychologists have also developed methods to subtly get around these explicit self-reporting biases. But self-report, behavioural, implicit, and physiological measures can all be combined to give us a rich understanding of how people think and act. We can compare groups statistically to determine if differences that are found are actually real or just due to chance. These methods are just the same as what other scientific fields use (though self-report is generally limited to psychology—physicists have a hard time asking protons and neutrons what they think).

2. Psychology uses experimental study designs that include random assignment and controlled manipulations.

The birth of the controlled scientific experiment was an enormous leap forward in people’s ability to draw conclusions about cause and effect the world. Two key components of an experiment lead to its importance: manipulation of variables and random assignment. The first, manipulation, ensures that we compare two or more groups that have one important difference between them. For instance, we could give one group of people a drug and another no drug and then measure the differences.1 The second component, random assignment, ensures that any differences that might still exist between the two groups (other than the effects of the drug) would only be due to chance. In other words, it makes sure that the two groups are the same in all other respects, so we know that any differences are due to the drug. It is a powerful design that rules out many alternative explanations. And psychologists use them all the time. Certainly there are other methods that psychologists and other scientists use (correlational studies and quasi-experimental designs, to name a couple), but psychologists love using experiments just as much as any chemist or physicist does.

3. There is a peer review process within psychology.

All the major psychology journals use the same peer review process that is found in other scientific fields. How it works is that when an manuscript gets submitted to a journal, the journal editor will send it out to two or three other researchers that also study the topic at hand. They take a look at the manuscript and give a review that assesses how much of a contribution the research makes, and how rigorous the methodology is. They send these reviews back to the editor, who makes a decision about whether to accept or reject the paper (or ask for revisions).

More importantly, however, psychology’s real peer review comes when the article actually gets published. Then, everyone is able to read it, discuss it, make critiques of it, and develop new research to test it further. This is, of course, how science is done! It’s a cumulative process that involves the field as a whole.

4. Psychology has both strong theoretical and strong empirical emphasis.

Freud and PiratePsychology is fairly well-known for its theories. Freud had his interesting (though incorrect) ideas about repressed childhood memories, virtually everyone has seen Maslow’s hierarchy of needs at some point, and Pavlov’s work on classical conditioning has led to the common expression, “hungry as a salivating dog in a lab experiment.” (Okay, I just made that up.) Psychology has since moved from an emphasis on broad, overarching theories that attempt to explain everything, to smaller theories that try to explain more specific human behaviour. But it has retained a strong emphasis on theory as a driver of scientific advance in the field.

At the same time, however, psychology in more recent years has tended to stay very “close” to the data. Theories are formulated, but they must be tested, and the data must confirm the theory. A psychological theory without empirical support tends not to have a long shelf life. This emphasis on empiricism is in line with the “hard” sciences, and in contrast to some of the other social sciences, which often have a very strong theoretical tradition, but less emphasis on data. It is my opinion that both theory and data are crucial for making a field scientific.

5. Psychology builds on previous research and also sometimes overturns past theories.

Psychology is a dynamic field that is constantly in flux with regard to the understanding of phenomena. As mentioned, psychologists often build off each others’ research and develop new tests of theories or new directions and applications for a theory. But this also sometimes involves the disconfirmation of theory. In some cases, theories are tested numerous times, in numerous ways, and found not to have empirical support. Thus they lose credibility and fade out of the picture.

With that said, the complexity of psychology as a field does lead to a multiplicity of theories covering the vast range of human thoughts, attitudes, and behaviour. This is in contrast to some of the other “hard” sciences that often have an overarching framework within which most research is done (e.g., the standard model in physics, evolution in biology). The complexity of the human mind and of human societies means that there are often theories which gain initial support, but the results cannot be replicated or are found to be limited to certain situations or populations. Because there are always new situations to be found and new ways of interpreting situations, it does lead to a bias toward generating theories and a bias against falsifying them. However, this problem is not disastrous as long as there is enough research done to find theories which apply over a broad range of situations and populations. As this sort of research is carried out, the more widely applicable theories generally rise to the top, even if other theories are not strictly “falsified”. Since the primary purpose of a theory is to offer a useful explanation of a phenomenon that offers new predictions, what is more important is that useful theories stick around. Psychology operates like any other science in this regard.

6. Psychology aims to make the world a better place.

This, I would argue, is one of the main purposes of science: to make the world a better place. Often science does this indirectly, through a better understanding of how the world works that only later develops into concrete methods for improving our lives. But all in all, science is about increasing knowledge and, in so doing, making life better. Psychology certainly aims to do this as well. Research on well-being has focused on finding variables that a) contribute greatly to individual well-being and b) are malleable. Research on stereotype threat has identified one reason why women and minority group members are underrepresented in academics, math and science in particular, politics, and upper management. Political psychology has attempted to find ways for liberals and conservatives to find common ground based on shared values. All these areas of research and more have had a great impact (and will continue to have greater impact as we uncover more knowledge) on society. How could it not? Finding out how people work puts us in a better position to make our environment better suited to human flourishing.

But more importantly, I think, is that psychology has changed how we conceptualize ourselves as human beings. Past ideas about human nature have presumed that humans are ultimately rational, are fundamentally good (or bad), and are born as “blank slates”. Psychology has shown us that our intuitive understanding of who we are is wrong. Humans are guided by emotions and intuitions with a thin slice of rationality on top; we all have a capacity for great good and great evil, but the extent to which we are one or the other is often a matter of the situation and the context; and we are born “hard-wired” with functions to capture meaning from the world in certain ways. Psychology has changed how we see ourselves, bringing us a more accurate and nuanced understanding of how we think and behave.

Human Nature: Machete Juggling

A Few Caveats

I think that the above points demonstrate fairly clearly that psychology is indeed a science. Of course, it is not a perfect science, and there are issues with how psychology is performed and represented to the public. Here are a few reasons why that is the case.

1. Science journalism sucks, and psychology is often misrepresented.

It’s no secret that science journalism is often not very good. With news organizations having to make cuts, dedicated science journalists are often the first to go, leaving journalists who do not really understand the research to write news items about it that mislead the public. It’s difficult to say just which science gets misreported most often, but psychology is certainly not immune to misreporting. The problem is twofold: a) journalists look for a catchy story, not necessarily the correct story, and b) journalists make little distinction between preliminary studies and more well-established research. Psychology tends to be affected quite a bit by the first aspect, because psychology research is inherently “catchy”. Journalists look for a way to apply the research to a general audience, and psychology is relevant to anyone who has a brain and lives on earth. Thus, reporting on psychology research can end up taking a very early, preliminary study on a select population and trying to apply it to everyone in the world. I’m sure you can see why a study asking participants in a speed dating event one question about who they liked best does not determine the factors that all men and women find attractive in others. Journalists have a tendency to extrapolate far further than is warranted by the actual research. But this leads to the impression that psychology itself is doing bad science and just making stuff up.

2. There are bad psychologists out there, just as there are bad physicists and bad biologists.

Of course, not all psychologists are doing good science. Psychologists are people too, and some of them are guilty of having their own pet theories that they advocate regardless of the data, or engaging in petty squabbles with other researchers, or using inappropriate statistics or methods in their research, or even fabricating data outright. These things happen, but they happen in every scientific field.  With the enormous number of scientists out there, every field will end up with some scientists who just do bad research. So even though there are several psychologists that have recently been caught manipulating or fabricating data, the fact that they were caught and forced to resign testifies that a) the field has standards that are enforced and b) the majority of the field cares that these standards are followed. I think that is ultimately a positive message.

3. The problems in psychology are active topics of discussion within the field.

Within the field, there has recently been an enormous amount of discussion about several of the problems with how psychological research is done. Problems with lack of proper replication, lack of transparency with data and statistics, laxity with standards on how to report data that have been dropped from a study, the use of non-representative samples to make generalizations about “people in general”—all these are issues that have been topics of active discussion and debate. But while it is troubling that these issues exist, it is encouraging that they are openly acknowledged as problems that need to be resolved. Some of these problems exist in other fields of science, and some have promising solutions that other fields have generated and put into practice. But the point is that these problems are not being swept under the rug. Psychology is full of scientists who disagree on a great many things, but who still care about doing good science. And that is ultimately the important point. Science is an imperfect and inexact process, since it is run by imperfect and inexact human beings. But psychology, along with other scientific fields, is continually on the road toward fixing the problems that exist in order to more accurately understand the world around us, and the world inside our minds.

Pot and Kettle Therapy: For the record, I never once called you black.


  1. Ideally, of course, we would want to compare the drug condition to a placebo group that was given something they thought was a drug. I’m just trying to keep the explanation simple. But psychologists use placebos too. []

5 responses to “Is Psychology a Science?”


Even though I know it was a tangential point, I’m coming to a mild defence of Freud because there’s little need to be apologetic about him. Instead we should be embracing his contribution to psychological science.

First, he used the clinical case study method that, while not experimental, is a common methodology in medicine and clinical psychology– though he wasn’t quite as aware of (or constrained by) its limitations as we are now.

Second, a brief list of ideas that originated with Freud and have been confirmed by modern experimental psychology:
– much of mental life is unconscious
– cognition is shaped by affect and emotion, especially ambivalence
– adult psychology is shaped by childhood, in particular romantic attachments and personality
– the mind contains mental representations of our selves, others, and relationships.
– the associations between mental representations operate in parallel, with both excitatory and inhibitory connections between concepts
– socially unacceptable impulses are often converted into their opposite
– personal motivations and attitudes are projected onto others
– facts and reality are readily denied when they conflict with self-perceptions
– aggressive impulses are displaced from their source onto less powerful targets

Cheers 🙂


Fair enough, Justin. Freud definitely was a pioneer for a lot of ideas that were later confirmed by experimental data. Of course, he also had some very wrong ideas that hung around a lot longer than they should have. But you’re right, and I think that it’s important to keep him within his historical context. He and many of the other early psychologists were stumbling around in the dark, with little theory or data to go on. So given those conditions, it’s quite impressive the impact he had.

I suppose my dig on Freud was not so much to “apologize” for him but rather to emphasize that the field has certainly moved past him. Even for the ideas that you list, we’ve moved entirely beyond Freud’s input on the matter. At best, he might be mentioned in the introduction to a paper. So…not an apology, just a reassurance that psychology has not gotten stuck on Freud’s ideas. 🙂


I’m just doing some lighthearted conscious raising. There’s just a weird tendency to minimize Freud’s contributions when we don’t do that for other people. For example, Piaget often used the same methodology–the Origins of Intelligence in Children is almost entirely based on observations of his own children!– and Elizabeth Spelke made a career showing that what Piaget said about object permanence is wrong. But Piaget is taught without the scorn that Freud gets. (Not saying that’s what you were doing!) Darwin still gets credit for discovering evolution even though biology has moved significantly beyond what he proposed.

People just forget that Freud was right (in broad strokes) about a good many things. A Freudian might argue that people are motivated to dismiss what he said because a lot of it makes people uncomfortable and raises their defence mechanisms 😉


A little late to this party, but…

I think there’s still an interesting question as to why some people — particularly physical scientists — think psychology isn’t a science. One reason, I suspect, is due to the lack of lots of reasonably-predictive mathematical theories. For this, I blame the mathematicians! The problem is that the math that works for other fields (like physics) simply doesn’t work for psychology (as those many physicists who decide to try their hand at psychology learn to their chagrin).

Another reason, I think, is that many people instinctively believe that human behavior is beyond explanation and understanding. They believe psychology must not be a science because they believe there can be no science of psychology. Which is a depressing viewpoint, and one I think we’ve proven for over 150 years is incorrect.

More on this here.


I think this article’s motivation—the questioning of psychology’s claim to scientific status in light of exposed cases of charlatans—is interestingly informed by the more recent article about correlation and causation.

People may be inclined to see a correlation between psychology and charlatanism. But is it causal? And which phenomenon—working as a psychologist, or being a liar—causes which?

I suspect that the social sciences, either by dint of being overly dependent on theory, or by insufficient self-policing, double checking and corrective feedback, are simply easier targets for those with intent or willingness to use less rigourous techniques to defend their theories. I could go so far as to say that dishonest people might choose psychology as a career for that reason, but more likely they fell into it by accident, and when they didn’t get caught, continued with that strategy (of making it up).

I think we can give social science the benefit of the doubt, owing to its much more complex and diverse subject area. In some ways, the aspirations of the field may be too great, and with all the research going in so many different directions, and most researchers undoubtedly preferring to break new ground over retreading old ground, there are a lot of opportunities for bad science to slip between the cracks.

Great post!