We have all been there. You stand in the supermarket, scanning the checkout landscape like a grandmaster surveying a chessboard. You spot it: the short line. Three people, modest baskets, a cashier who looks caffeinated. You commit. Two minutes later, the woman in the “long” line next to you is already paying and leaving. Meanwhile, your cashier has called for a price check on an unscannable item, and the person in front of you is counting out pennies. At that point it no longer feels like bad luck, but like the world is against you. But as it turns out, your frustration isn't just a mood; it’s a fascinating intersection of psychology, social justice, and cold, hard probability.
The Equation of Misery
To understand why we feel so wronged, we have to look at the work of David Maister, the "founding father" of waiting psychology. Maister proposed a deceptively simple formula for the human experience of waiting:
S = P - E
In this equation, S stands for Satisfaction, P for Perception, and E for Expectation. If your perception of the service you receive is higher than expected, you are happy. While a lower level of service (longer waiting time) than expected makes you feel unhappy.
Maister noted several psychological quirks that skew this equation. For instance, unoccupied time feels longer than occupied time. This is why mirrors are placed next to elevators and why Disney World fills their long queues with distractions. He also pointed out that anxiety makes waits seem longer. The moment you start wondering if you picked the wrong line, your anxiety spikes, your perception of time dilates, and your satisfaction (S) plummets before the line has even moved.
The Great Injustice: Social Slips
The psychological pain of a slow line reaches its peak when we talk about Social Justice. In a perfect world, the first person to arrive is the first to be served. But in a multi-line system this justice is constantly violated. Someone arrives minutes later than you, but their cashier is faster or the people in that line have less items and thus they are served before you. This transforms a boring wait into a perceived injustice.
The 1/n gamble: you are statistically unlucky
If you feel like your line is rarely the fastest and feel very unlucky about this, consider the statistics behind this. If there are three lines at a store, there is only a 1 in 3 chance that your line will be the fastest. That means there is a 2 in 3 chance (66.7%) that one of the other lines will be moving quicker than yours. If there are five lines, the odds that you are in the fastest one drop to 20%.
Statistically speaking, you are almost always betting against the house. But lets say you are lucky for once, and have entered the second fastest line in a system of 20 lines. But the fastest line is right next to you, so in your perception it is still unfair. This occurs because we tend to ignore the lines that are slower than ours and focus entirely on the one that is beating us, meaning that we live in a constant state of perceived statistical failure.
The Last Place Aversion
Even when we know the odds are against us, our brains find new ways to make the experience worse. Harvard researcher Ryan Buell discovered a phenomenon called "Last Place Aversion." We absolutely hate being at the very end of a line. It feels vulnerable and inefficient. Buell’s research showed that people are four times more likely to switch lines when they are in last place, often making a lateral move to another line that looks about the same. However, this is almost always a mistake. His data suggests that people who switch lines out of a desire to stop being last end up waiting significantly longer than if they had just stayed put, by up to 67%!
The Solution
If we wanted to solve the Queue Jumper problem, the answer is mathematically simple: the Serpentine Line. This is the single, winding line used in banks and airports that leads to multiple tellers. It eliminates the 1/n gamble as everyone entering behind you will get served after you. It also removes the anxiety of choice. Yet, many retailers avoid them because a long, winding line looks more intimidating than five short ones, and if lines are visible before entering a store it might scare customers from entering.
So, the next time you’re standing in the "slow" line, watching a latecomer breeze past you, take a deep breath. Remember Maister’s equation, accept that you are statistically always unlucky and definitely do not switch lines!