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.