Argh. I know that if you are reading this, you are probably some kind of scientist or engineer, if not by trade then at least in mindset.
You are probably not a social scientist. I am. There are not many of us on Slashdot. So please, take a moment and let me explain a bit about our work to you:
It's true, correlation does not imply causation. However, not every SS study is a correlative study. There actually are ways to measure causation. Even ones that don't require a perfectly randomized full experiment, which is very hard to do when dealing with human subjects and nearly impossible to do if you're trying to find out how things work in the real world rather than how they work within a particular laboratory setup. There are many methodological and statistical techniques for piecing apart the likelihood of a correlation pointing to causation.
In addition to that, plenty of studies that do not measure causation don't claim to be. Now, the press release put out by their university might. The random blogger who posted about it might. But that doesn't mean that the authors actually claimed to find causation with methodologies that can only find correlation. Generally, that kind of thing gets mentioned in the peer review process.
So please, the next time you see a psychology/behavioral/education/other social science study on Slashdot, do not automatically cry "Correlation does not imply causation!!" without even reading the paper or understanding their methodologies or what they actually did or did not claim. And REALLY do not use this as your entire justification for declaring the study completely illegitimate. You just sound like a creationist who has wandered into a discussion of evolution and yelled "But what about entropy???"