One of the science blogs on my google reader published an interesting review on PCR. PCR is a widely used technique for quickly replicating and examining DNA samples. The review is very much worth a read: check it out here.
First, the guy on acid thing doesn't even begin to cover the crazy that is Kary Mullis.
Second, this description is interesting in how much it highlights how completely problematic and subjective the "hard" sciences can be.
Psychology as a Science
My big science pet peeve (other than terrible puns in journal article) is when people insist that psychology is a "soft" science or generally unscientific. Ignoring the blatent philosophical hypocrisy of using these labels without operationalizing them, separating psychology from biology, chemistry, and physics creates a false dichotomy. To do the work that I do I have to learn, and be able to critically assess, material from fields as varied as neuroanatomy to chemical messaging to MR physics. True, some fields of psychology share more characteristics with sociology and political science than the biology-oriented stuff that I do, but that doesn't mean that they don't apply the scientific method.
Subjectivity in the "Hard" Sciences
What I think the PCR article shows nicely is how all science, even the "hardest" of sciences, are built on assumptions. Building on these assumptions is what allows science to move forward (well, maybe). That Psychology is more open to the notion that its principles are just assumptions that may be altered or thrown out in the face of opposing evidence makes it epistemologically honest, not unscientific. The techniques of physics, chemistry, and biology are, like those in psychology, are based on sets of assumptions and open to subjective interpretation. To claim otherwise demonstrates either a lack of understanding as to how science really works or a failure of critical thinking.
Folk Psychology and Pseudoscience
Now, with all that said, I'm not going to pretend that there is nothing unscientific happening within psychology. Studying human behavior seems to lend itself to more a more philosophical discourse than something like the study of plants or chemical reactions or whatever. However, this sort of thing is unscientific because it doesn't follow the scientific method (which itself is built on a set of assumptions by the way) not because it is psychology. Just as there are are unscientific elements within psychology, there are equally (if not more egregiously) unscientific elements within fields that are widely regarded as objectively scientific.
A Note on Voodo Correlations and Marc Hauser
I don't mean to lump these two things together, but they I think they highlight the scientific nature of Psychology. While the Voodo Correlations business was ridiculously overblown, it did make researchers think critically about their methods. This doesn't make Psychology unscientific, it just means there is an open (though overdramatic) dialogue about what methods should be used in what setting. The Mark Hauser thing just demonstrates that Psychology data, like any other kind of data, is open to being faked. The fact that Hauser's students (or assistants, I'm not so clear on this point) turned him in, demonstrates more open dialogue. That these dialogues exist doesn't make Psychology unscientific, if anything it makes it more scientific than fields where such discussions either don't occur or are actively suppressed.
This isn't why I insist on calling myself a scientist, I just do that because I'm obnoxious.