Field of Science

Is psychology a science?

Is psychology a science? I see this question asked a lot on message boards, and I thought it was time to discuss it here. The answer depends entirely on what you mean by "psychology" and what you mean by "science."

First, if by "psychology" you mean seeing clients (like in Good Will Hunting or Silence of the Lambs), then, no, it's probably not a science. But that's a bit like asking whether engineers or doctors are scientists. Scientists create knowledge. Client-visiting psychologists, doctors and engineers use knowledge. Of course, you could legitimately ask whether client-visiting psychologists base their interventions on good science. They often don't. But that can also be said about doctors and, I'd be willing to bet, engineers.

However, there is a different profession that, largely for historical reasons, shares the same name. That is the branch of science which studies human and animal behavior, and it is also called "psychology." It's not as well known, and nobody makes movies about us (though if paleoglaciologists get to save the world, I don't see why experimental psychologists don't!), but it does exist.

A friend of mine (a physicist) once claimed psychologists don't do experiments (he said this un-ironically over IM while I was killing time in a psychology research lab). My response now would be to invite him to participate in one of these experiments. Based on this Facebook group, I know I'm not the only one who has heard this.

There are also those, however, who are aware that psychologists do experiments, but deny that it's a true science. Some of this has to do with the belief that psychologists still use introspection (there are probably some somewhere, but I suspect there are also physicists who use voodoo dolls somewhere as well, along with mathematicians who play the lottery). The more serious objection has to do with the statistics used in psychology.

In the physical sciences, typically a reaction takes place or does not, or a neutrino is detected is not. There is some uncertainty given the precision of the tools being used, but on the whole the results are fairly straight-forward and the precision is pretty good.

In psychology, however, the phenomena we study are noisy and the tools lack much precision. When studying a neutrino, you don't have to worry about whether it's hungry or sleepy or distracted. You don't have to worry about whether the neutrino you are studying is smarter than average, or maybe too tall for your testing booth, or maybe it's only participating in your experiment to get extra credit in class and isn't the least bit motivated. It does what it does according to fairly simple rules. Humans, on the other hand, are terrible test subjects. Psychology experiments require averaging over many, many observations in order to detect patterns within all that noise.

Some people find this noisiness deeply unsettling and dislike the methods social scientists have developed to compensate for it, and thus would prefer to exclude the social sciences from the term "science." This is fair in the sense that you can define words however you want, but it does mean that a great deal of the world -- basically all of human and animal behavior -- is necessarily unexplainable by science.

So what do you think? Are the social sciences sciences? Comments are welcome.


Anonymous said...

I'm a little bit late for a comment, but I think you might be interested in the discussion on Andrew Gelman's website:

There I added my own comment (wolf); I'm a psychologist myself. Even though the criticism "psychology isn't a science" is somewhat ridiculous, I still agree with Andrew and others that psychology's achievements have been rather scant, at least in terms of usefulness (if you don't count ergonomics and the like).

However, I don't think that it's just the signal/noise problem and lack of precision of instruments. Even before that there's a "noise" about what are the phenomena of interest; e.g. if you want to study intelligence, you do not only have to cope with unreliability --- no one can say (and I myself seriously doubt) that intelligence is "really existing" as an entity that could be studied by other means than a psychological test.

Rana said...

Obviously psychology is a science not just because it "does experiments" but because it offers hypotheses that are either verified or dismissed by the evidence.
The statistics point is interesting - even the "purest" science does not offer anything more than a probability of an outcome - Avogadro's constant is large so the probability of a repeated result is pretty much 1. But if you can predict a subsequent event then the principle is the same.

DD5 said...

First, I think the answer depends of how different branches of phychology conducted their research. Mainstream Psychology during most of the 20th century did not apply the scientific method! freud theory of personality, behviorism, etc.. are examples of why phsycholgy got such a bad rep in terms of science. such theories, which highly influenced society, were never real scientific theories since they were never based and grounded on scientific research..(such as controlled experiments). This is why they were easily refuted by other branches and spinoffs of brain science that actually did apply the scientific method: behavioral genetics, cognitive science, evolutinary psychology, neuroscience, and even pure biology and genetics.. It's actually quite embarrassing.

Second, I don't like the analogy between engineers and doctors! Engineering is about design and development of complex systems by applying scientific priciples. Evolution by natural selection is actually a natural engineering process. much of science is actually about the reverse: reverse engineering of complex designs, such as the brain sciences. Engineers don't have much leverage in applying guess work, or intutition such as doctors, in order to accomplish their task. would any of us get on an airplane or cross a bridge if engineers didn't rely on pure hardcore science?

josh said...

dd5: Thank you (and everyone else) for reading and for your comments.

I am curious as to what you mean by "mainstream psychology." Certainly, psychology as portrayed in the mainstream media and popular consciousness in the 20th century was not particularly scientific. You get a very different since if you look at professors at the major universities or look at what was being published or what was being published in journals. I just spent the last week reading articles from the early 20th century, and I was surprised by how much even in journals dedicated to counseling reported hard, empirical evidence.

Furthermore, you mentioned Behaviorism. I am not sure how Behaviorism is non-scientific. If any thing, they suffered from too much science. They tried to banish concepts for which they felt they had no evidence, like thoughts and beliefs. Ultimately, such theories were unworkable and were replaced...which itself is evidence of the scientific method at work.

I think it would be very interesting to know why you consider evolutionary psychology to be a better example of science at work. I am a fan of evolutionary psychology, but at the moment I can't think of a single testable hypothesis that has come out of that field. Whereas I can cite a number of influential experimental results from Behaviorism.

However, I'm not an expert on the history of psychology. So I would be very interested in what you or anyone else has to say on the subject.

bloggin the Question said...

I'm interested that you say that the use of introspection in psychology, or the suspician of it, makes it dubious as a science, likewise statistics. However, introspection, whilst to be avoided in physics, might be seen as irreducibly the phenomena under investigation in psychology. I could make the claim that to have a mind, of the interesting sort, is just to be able to introspect.
A good scientific approach to psychology should, when it focusses on introspection, involve a lot of "comparing of notes". Popular poetry and song lyrics should be given a lot more attention than they are, since here we have inter personal approval of forms of introspective expression.

josh said...

Hi Blogging the Question:

I agree that the subjective experience is part of what we want to study. The question is whether introspection alone is a good method of learning about it.

The method of studying psychology you suggest is something like what Helmholtz (arguably the founder of cognitive science) used in the 19th century: introspection and the comparison of notes. He managed to make some important discoveries (such as, that we have photoreceptors for three wavelengths of light).

However, Helmholtz studied phenomena that are relatively immune to bias and for which there is little variation from person to person (what color do you see?). Many of the interesting topics in psychology (social perception, language, memory) are prone to distortion. If you think too much about a memory, for instance, you will change it. People lie to experimenters (and to themselves) about social issues. And linguists are notorious for disagreeing with each others' intuitions.

So if I made a blanket statement that introspection is bad, that would be incorrect. But introspection is certainly limited, and can often lead researchers astray.

Anonymous said...

you are right about this, people always ask me the same question and some of them even question the effect of psychology just because they don’t consider it a science. my answer to them is, even the other fields that they call sciences have theories that are proven false over the time.

Anonymous said...

In my opinion, a "science" is any subject that seeks to find answers or explanations amidst an existence of unknowns.

This definition is admittingly very broad; however, I think that people in this world are so obsessed with specific designation of concepts that they often miss the "big picture." One definition can have an abundance of possible applications.

The primary goal of psychology is understanding - finding knowledge that can later be applied to improve the quality of life. This understanding can be achieved through observation and research, both of which involve experimenting skills typically applied in the more traditional fields of science (chemistry, biology, etc...)

So, yes, given my definition, psychology (along with most other disciplines) is indeed a science. I might even go so far as to say that psychology is one of the most difficult sciences, given the public's reluctance to recognize it as such and the numerous challenges of working with humans (as you have pointed out).

Anonymous said...

Considering all the possible and impossible stuff that goes uder the heading of psychology it is hopelessly inadequate to classify it all with one term.

There is a lot of psychological nonsense on the market, self help books that help writers and publishers and that's how far it goes. Nothing scientific there.

Then there is a growing body of scientific research going on in the physiology of perception, learning, processing information and -it was about time- emotions. Also the search for the neural correlates of consciousness necessarily includes a psychological point of view.

There are wackos in the field of psychology but there are quacks in medicine, buildings that fall down, ships that sink and spacecrafts that explode in midair.

Humans err. Psychology is the way to find out ways why they -we- insist on doing so, no matter how much solid evidence we are being presented.
If only we could apply the knowledge we already have!