Do shoppers turn left or right?

Walk into a supermarket and you join a current you probably never notice. Most of the people around you peeled one way at the door, slowed in the same spot, and traced a loop that the store designed for them years ago. Retail has spent decades arguing about which way that current runs, and the argument is more useful than it looks: the side a shopper turns is the side that gets shopped first.

The famous answer: turn right, go counterclockwise

The best-known rule is the “invariant right”. The retail anthropologist Paco Underhill, who spent years filming shoppers for his book Why We Buy, popularised the observation that people tend to enter, drift right, and work their way around the store counterclockwise. It is why so many big-box layouts put their seasonal and high-margin displays to the right of the entrance, and why the often-quoted figure in trade press is that the large majority of shoppers turn right.

There is a tidy story to explain it. Most people are right-handed and right-footed, so they push off that way. Right-hand-drive countries train a lifetime of keeping right. The eye, scanning a new space, tends to settle on one side first. Put those together and the rightward drift sounds almost like physics.

The catch: plenty of shoppers go left

It isn’t physics.

When researchers actually track entries rather than recall them, the rightward bias turns out to be weak, and in many stores the split between left and right is closer to a coin toss.

The counter-tradition is just as old: many supermarkets and department stores are deliberately designed to send shoppers left from the entrance, on the theory that a relaxed, leftward loop keeps people in the store longer. Whether that loop actually lifts dwell and spend is its own question, and its own article; the point here is narrower. The same industry confidently teaches both rules, turn right and turn left. That should be a clue.

The driving-side theory, and why it wobbles

A popular tiebreaker says it comes down to traffic: shoppers in right-driving countries turn right, and shoppers in the UK, Japan and other left-driving places turn left, because that’s how they move on a pavement and through a door. It’s a satisfying theory and there is something to it at the margins. But when it’s tested, the correlation is loose. In left-driving countries the first move inside a shop turns out to be less predictable, not reliably leftward, and shoppers respond more to what the shop shows them than to the highway code they grew up with.

What really decides it: sightlines, not instinct

Strip away the folklore and one factor keeps coming out on top: what the shopper can see from the threshold. A clear category, a bright display, a wide aisle or simply the obvious path pulls people far more strongly than any handedness.

Layout beats instinct.

The first few metres inside the door are also a poor place to sell anything, a zone Underhill called the “decompression zone”, where people are still adjusting from the street and tend to walk past whatever you put there. And once they’re moving, the gentle disorientation of a well-designed loop, sometimes called the Gruen effect, keeps them going long after the errand is done.

In other words, “left or right” is the wrong question. The right question is: in this doorway, with this sightline, which way do people actually go, and what are they missing when they do?

Measure the door, don’t trust the rule

This is exactly the kind of thing you can stop guessing about. With Wi-Fi-based people counting, the access points a store already runs become a sensing network: phones moving through the space emit signals that are anonymised and aggregated into routes, so you can see the dominant direction at the entrance, the heatmap of zones that pull attention, and the corners that never do. No cameras, no app, no one identified.

Then you can test, not assert. Move a fixture, reface the wall to the right of the door, open up a sightline, and watch whether the current shifts and whether more browsing turns into buying. For a chain, the same method shows whether the “rule” even holds the same way across every branch, or whether your flagship behaves nothing like your high-street stores.

The short version

Do shoppers turn left or right? Both, depending on the building. The invariant right is a real tendency and a weak one; the leftward loop is a real design choice; the driving-side story is half true. None of them tells you what’s happening in your own entrance today. The path data does, and because it’s the only footfall method in Europe approved by a data protection authority, it tells you without watching a single named person walk through the door.