You scan the checkouts, carefully analyse the options, confidently choose what looks like the fastest queue... and within seconds the person in the aisle beside you has paid, packed their groceries and disappeared into the car park while you're still waiting behind someone searching for a rewards card.
It feels like you're cursed.
The good news? You’re not.
Your brain is keeping score
When you're standing in a queue, your attention naturally drifts to the lines beside you.
Every time another queue moves while yours stays still, your brain notices. But when your own queue moves ahead and the others stop, it barely registers.
Psychologists describe this as a form of selective attention, and it can leave us convinced everyone else is getting through faster, even when the overall waiting times are very similar.
There's another mental shortcut at play too. Once you've convinced yourself you've picked the slowest queue, your brain starts collecting evidence to support that belief. Every small delay confirms your suspicion, while the moments your queue moves quickly, tend to fade into the background.
The shortest line isn't always the fastest
It turns out there's another trap.
Most of us instinctively count the number of people waiting, rather than looking at what they're actually buying. A queue with five people carrying baskets may move much faster than one with just two shoppers pushing overflowing trolleys.
Researchers have also found that the way queues are organised can influence how efficiently they move. Some studies suggest dedicated checkout lines can encourage faster service because each cashier focuses on their own customers, while other research shows that single, shared queues can reduce frustration by preventing one unlucky shopper from getting stuck behind a particularly slow transaction.
In other words, there's no magic formula, and appearances can be deceiving.
Why changing queues usually backfires
Almost everyone has experienced it.
You abandon your queue for one that suddenly looks quicker. The moment you switch, your old line races ahead while your new one grinds to a halt.
While it feels almost supernatural, probability helps explain much of the phenomenon. Every queue experiences random delays, from price checks and payment problems to forgotten items. If you switch because another line has just started moving, there's a good chance you've simply missed your own queue's turn to do the same.
Researchers have even found that people dislike being last in a queue so much that they'll often change lines, even when doing so is unlikely to get them out any faster.
So which queue should you choose?
If you're looking for the best odds, research suggests paying less attention to the number of people and more attention to what's happening at the checkout. A shopper with a trolley full of groceries, lots of fresh produce, or several separate transactions can take much longer than a handful of people carrying just a few items.
And once you've picked a queue, you're usually better off sticking with it. Though, that’s easier said than done!
SOURCE
Association for Psychological Science
Study on Queue Configuration and Service Time
Study on Last-Place Aversion in Queues
Study on Wait-Perception Bias