From the first sentence of the conclusion:

> It should be noted, however, that... the mean IQ for the GAD group was elevated in comparison to the control group (a mean of ∼119 versus a mean of ∼109). Further, the IQ means for both the GAD group and the control group were significantly higher than the average IQ of the general population (∼100). Results should thus be interpreted with the consideration that the study sample is non-representative of the general population.

I've always wondered about this when talking to friends of mine who are psychology grad students about the studies they work on. Since most of them rely upon volunteers attracted via mechanisms like flyers put up on a university campus or the raffle of a free iPad in a college town, aren't these types of volunteer-based studies going to tell you a lot about college kids and (potentially) very little about the general population?

Yep - college undergrads are the white mice of psychology, just not as cute (usually).

Exactly. And lots of studies (just hearsay) where smashed when trying to replicate them with a sample that mimics the general population.

Lots of psychology studies have failed to be replicated even in college students. The problem generally is not the population being studied, but the small numbers and a lack of control for bias.

I came to confirm that as well :).

Students lingering in the hall is the template of psych. models.

Yes.

So if I'm having high levels of anxiety and feel dumber every day, it means I'm not having a generalized anxiety disorder?

You could be experiencing imposter syndrome.