Flight landings & standing fetish?!

I just landed in chennai via a late n ight flight and the question is ringing again in my mind….WHY DO PEOPLE LEAVE THE SEATS AND STAND UP AS SOON AS THE FLIGHTS LAND STOP?

I m talking abt these people who start getting impatient as soon as the flight lands, start opening the seat belts (seat belt sign is on), switch on the mobile phones (you r supposed to wait till the doors open) and these same guys immediately get up; take their respective bags and stand in the aisle for 10 minutes or so, they have the choice to continue sitting and only get up after de-boarding starts, but due some internal insinct more than 50 percent of the people stand and waste their energies.

Whats the cause of this behavior? I can think of few reasons, would love to hear more views:

– Insecurity: they basically dont feel secure sitting down and think that by standing they can get out before others which is sadly not true
– New travellers : some of them are new and hence think doors will open as soon as the plane stops and they can get off.

UPDATE (03 March 08): My X-boss (jai kumar), send me a couple of good thoughts on this:

1. The “real” reason that people stand up immediately after the plane lands is to s-t-r-e-t-c-h. Sitting crammed in economy class for lengths of time leads to “deep vein thrombosis” (economy class syndrome) and “bruised inner thighs”.

2. Do you ever see Business or First class folks stand up immediately after the plane lands? Never. Guess why?