They have no concept of queuing.
I recall that we noticed this when holidaying in Holland and Germany. Even the Germans (not known for their queuing habits) used to get p*ssed of with the Spanish for pushing their way to the front of any queue. At theme parks etc (hate the paces but when on holiday one has to take the children to them) the Germans used to refuse to let the Spaniards in if they wouldn't wait in line.
Much the same applied to those from the Arab countries but there I think Herman had it right and kicked them to the back on principle ~ even if they had been waiting in line for hours.