Originally Posted by
Ber2dca
Priority boarding lines work with some limitations. It's like a mob of protesters held back by a handful of cops. It's kind of a bluff and thus a psychological test. The cops know they wouldn't be able to hold back the protesters if they make a charge but the protesters need the audacity to start the charge to begin with (as they don't know how many will join it and might be afraid of the consequences for themselves). Same with a priority line.
Doesn't really work though. The mere fact that you have to scan your boarding pass prevents the charge. I have also seen it with AA where people that do not have priority have scanned their boardng pass and it has rejected it. When the gate agent looks at it, they immediately point out that they are only boarding first class etc. So it would appear that there is some semblance of control to the actual process.