A couple days ago I asked whether psychology was a science. Many of the responses I got confirmed what I already knew from reading message boards and talking with other academics. Psychology must have done a terrible job of PR, given that so many well-educated folk and scientists in other fields have absolutely no idea what it’s about.
I commonly hear statements like “psychologists don’t do experiments” or “psychology experiments aren’t well-controlled” or “psychology experiments aren’t replicable.” Saying psychologists don’t use experimental controls is like saying that the existence of electrons is “unproven” or that evolution is a “theory in crisis.” Basically, the only way somebody could say something like this is if they are entirely ignorant of the field.
The big difference, though, is I doubt it’s widely accepted among biologists that electrons probably don’t exist or among physicists that evolution is an unproven, shaky hypothesis, but it does seem that an embarrassingly large number of physicists and biologists (and other scientists, too — I’m not picking on physics or biology) have similarly unfounded views about psychology.
(If you really need an example of a replicable, robust psychological phenomenon, try out the Stroop effect, which is also an example of an experiment with good controls. This is a bit like defending evolution, though. Leafing through any reputable journal should be sufficient.)
So why care if people are ignorant of psychology? For the same reasons it’s important that they be informed about every branch of science. First, there’s a lot of information there that would be useful to people in their daily lives. Second, if people don’t understand and value a discipline, they’re less likely to fund it. Science in America is largely funded directly or indirectly by the public. If you believe a particular science is important for the health of the country, then it’s important that enough voters also value it.
On the question of replicability, it’s true that some results in psychology don’t replicate, sometimes because the results were a fluke and sometimes because the experimenters made a mistake. I wonder, though, if it’s actually less common in other fields. In physics lab in college, my lab partners and I measured the speed of light, getting an answer way different from the accepted figure (no, we weren’t even within measuring error of the correct number).
So that’s at least an existence proof that it’s possible to do an experiment in physics that won’t replicate (that is, our experimental results don’t replicate).