Economists thinking about sex

I came across this piece by (non-economist) Grover Cleveland at the Pileus blog. Cleveland writes,

I was stuck at the airport for much of last Saturday and so perused the magazine racks there at some length during breaks from the pain of trying to work in an airport chair. At one point, my eyes wandered over to the newest edition of Psychology Today - a pretty awful magazine - and noticed the front cover advertising an article titled something like: Why Smart People Have Less Sex. (Emphasis added)

Well, this just goes to proves I must be a genius! :-(

Cleveland goes on to note that

I instantly and without really thinking at all said to myself, “Well that must be due to their higher opportunity cost,” before I even processed anything on a more intellectual level or even picked up the magazine. I decided to see if the article did touch on this (obvious) possible explanation and was disappointed during a quick perusal to see it wasn’t really discussed as an alternative in anything more than a cursory fashion.

May be I should point out that the tile of the Cleveland's article is "I’m spending too much time around economists". Personally I don't see how that's possible, but may be that just me.