Ananova reports,

Siegfried Lehrl, of the University of Erlangen and Nuremberg in Germany, says sunbathing and relaxation lowers your IQ.

He told Berliner Kurier: “Fourteen days of complete rest can be enough to bring your IQ down by 20 points.”

Mr Lehrl agrees people who work hard all year need some time to relax.

But he says they should avoid getting bored while on holiday, since boredom affects intelligence.

He told the newspaper paper: “Boredom is a warning signal when we feel a lack of mental challenge.”

Mr Lehrl recommends a daily round of backgammon, or taking a book along to the beach to stay smart.

You never saw Chevy Chase reading or playing backgammon in those National Lampoon Vacation movies, did you?

Of course, one wonders if Lehrl hadn’t just returned from a rather lengthy does of sunbathing himself.

(Hat tip: Venomous Kate)