Teen-rated games also find their home on the PSP. The DS only has 31 Teen-rated games, while the PSP has three times the number of titles, with 96 T-rated games.
While it's undeniable that the DS is selling better than the PSP, one has to wonder how many of those consoles are for adults. I'd assume not too many. Grand Theft Auto sold over a million copies on Sony's handheld, while LocoRoco went by mostly unnoticed. I think it should be pretty clear that the two portables are targeting two very different markets: and older gamers, like myself, enjoy the slightly more adult-themed games of the PSP.