It's true, the Daily Mail is not exactly known for being reputable. I had the same reaction Ong, but then figured I ought to at least check out the National Marriage Project. Despite its name, it doesn't seem ideologically-driven or biased (although if you actually
read the study, which I did, the language vaguely suggests otherwise... Hard to tell where their motives lie)
What's important to assess is
why satisfaction rates drop, not if. The possible reasons are myriad, and probably have a lot to do with our sexually repressive culture. After all, 22% is just fine.
(I originally wrote "repressively sexual" culture which makes me laugh, totally opposite meaning haha. Although on second thought maybe there is a truth in that wording as well...)