What's up with thumbing one's chin whilst playing chess!?

Kasparov used to squeeze his earlobes, I think because there was a theory about acupuncture that said it improved thinking. So that's two hands to squeeze your earlobes, one thumb on your chin, one hand to move the pieces with ... Good job they banned mobile phones.

in the last photo noitice Najdorf with the double thumb under the chin! After seeing that, I now understand why he was a bad ass for so many years.

I go for the double thumb manoever, essentially the same thing. 

Add to the list this young unknown player.

I have noticed many chess players have nervous " ticks " and some are not even aware of them. I have seen some players that constantly twirl a lock of their hair, some shake one, or both, legs under the table and some are constantly twirling a pawn or some other captured chess piece while they play. I have been told that I am one of the leg shakers myself......  what are some other such habits y'all have noticed ? 

Ivanchuck is obbsessed with picking his nose, watch interviews and shots of him at the board, he constantly fiddles, scratches, digs, wips, picks, inspects, flicks and manipulates his nose and nose contents...very gross, ive been around coke-heads before and theyre not QUITE the same movements but very similar...maybe a old habit from back in the 80's...maybe he did have a reason to throw a fit over the dope test too......nah CHUCKY FOR WORKD CHAMP!

 lol mangnus carlson unknown player that makes me laugh

http://www.youtube.com/watch?v=MEVuAGY90Dg

http://www.youtube.com/watch?v=kH3e60KtxTU&feature=related

the chuck diggin it

I see what you mean.

It would be pretty awful if you went to capture Chucky's Queen to discover a plump, glistening booger sitting on top of her crown.

(Now where's the emoticon for retch?)

 lmfao  the second one was funny, hes in an interview and he picks his nose for 1 sec, i didnt see the rest but it looks like he was desperate to pick his nose.