This is such a joke ... and a few of us are laughing.
Hardly ANYONE can do this.
Its an old "trick" of sorts. Kind of like that trick where men can't bend over at the waist with their head against a wall, pick up a chair, and "right" themselves.
This is a trick question, it makes the respondents feel as if they are either:
... not flexible (right sure, I know many flexioble people who cannot do this either) or
..... like super-buffed, when most skinny geeks or fatty .. hell.... almost 99% of the population .... cant do this either!
Its a joke question guys, been around for years.
Its been used also in various mind-trick scenarios ... where someone looks at a person and says "hm, .... I'll bet you cant touch yoru elbows together .... can you?". The person (subject) tries, and ..... WOW ......... he CANT! Who would have guessed?!?!?!