Fascinating. By standing in the expert line, people seem to make more of an effort to follow directions to ensure they aren't the jackass poser "expert" who holds up all the other real "experts".
2 days ago, I was behind the worst passenger ever in the expert line. It took him 2 minutes to dump all his crap into 5 trays and then 6 attempts to make it through the xray machine. I think he's still looking for his shoes.
This effect last seen in your neighborhood grocery store. Want a shorter wait? Get rid of some of that crap so you can stand in line for the express lane.