Well, it looks like those are the averages for "intended" major so keep in mind those are not necessarily people who actually got in. Not to mention it does not separate master's from doctorate. Plus I'd wager we have more issues with degree-mill and almost-degree-mill type schools than most majors. It doesn't surprise me terribly - I think even legit psychology programs do get a fair number of "What the hell, why not" kind of applications since there are relatively few hoops you have to jump through to apply, even if there are many for actual acceptance.
One need only look at the math/engineering ones to know something is a bit odd though. A 730 quant is absolutely horrific for someone planning on grad school in a mathematical/technical field. My girlfriend is in that area, and was considering retaking it because she got a 780,which actually puts her below the mean for accepted students at most of the places she wants to go.