One commenter argued that these might be lower risk funds, but that doesn't really make sense to me. Low risk funds should do better in 2008 as they should weather out the crash, right?
This fits with my personal experience. I had some old mutual funds that got hit harder than the new index funds I'm putting my work retirment funds into. I'm trying one socially responsible fund, it's doing pretty well, although I'm willing to take a slight hit on perfomance in an attempt to funnel more money towards green industries and such. That said, I do think I should do some extra research and make sure that the fund is exploiting their stockholder voting power and such.
On a related note, I forget if I've mentioned this before, but I did learn an interesting financial company trick at an Edward Tufte class. He used sparklines, a neat visualization tool, to show that many mutual funds basically followed the index funds, presumably these include the one that aren't underperforming. Why might that be? Well, by shear luck a good percentage of fund managers should beat the market in any given year. Over time, even with no special skill, some of those funds will get a good record. You then drop all the funds that were underperforming (sometimes due just to bad luck) and keep the winners. If you want to save staff time, you can switch a mutual fund over to just following the market. The way Tufte described it, it sounds fairly malicious, certainly not what people are paying for. However, given the perfomance numbers listed above, maybe everyone's better off that way.