This
BI Article about Delta's boarding groups alleges that
- The system was designed to make the boarding process more efficient, but it's been making some passengers more stressed out.
- When Delta puts too many people in one boarding group, it makes other passengers worried that the plane will run out of space for carry-on items before they board, and increases the odds that passengers will become hostile.
Is that true? Is there empirical evidence that lining up causes more air rage incidents???
As noted here, it can engender a fierce sense of competition. I used to get anxious while waiting for my number to be called (and still do after all these years). So I suppose I'd be less anxious if I didn't see half the airport sprawled across the boarding area and beyond!