Supermarkets are part of our everyday lives and we generally take them for granted.

Each time we take a trip to our local store the brightest retailer and manufacturer brains are actively managing every aspect of the store in order to influence our buying behavior subconsciously.

When you ask people how much of a supermarket (how many aisles) they visit when they go shopping, a large proportion will tell you that they visit nearly all of it. In fact this is far from the truth. We know this from studies of shopper behavior in supermarkets which use CCTV video footage to monitor shopper traffic.

In fact when we enter a store we generally navigate a route around its perimeter, be that clockwise or anticlockwise depending on the country in which we live, and dip in and out of the central aisles according to our needs. This perimeter or “race track” is designed to have a wider walkway both to accommodate a larger amount of footfall but also to encourage our behavior since we naturally tend to migrate towards open spaces and avoid confinement. Retailers know this and make sure they position their key products, the things they know most people will buy, such as meat, produce and bread on the race track so that as many people as possible are exposed, and end up buying from these product categories. For the manufacturers of branded products such as baked beans or soft drinks the race track is also a desirable place for their products to be positioned in order to gain maximum exposure to shoppers. As such this space is highly sought after and brand owners must propose attractive discounts in order to secure this space for even a short time window.

The central aisles of the store, because they are less widely and frequently visited by shoppers actually account for proportionately less of the sales of a typical supermarket than you might think. Most of the products in the store, those in the central aisles, actually do not sell in high volume and consequently the aisles in which they reside are said to have a lower “sales density”. This lower volume majority of products are what is known as the “long tail” of the product offering. However it is not to say that the long tail is inconsequential. Whilst relatively few units of an individual product in the long tail may be sold, these products do serve the purpose of catering to every eventuality and in doing so also give us as shoppers a sense of variety which drives us to choose that store over another in the first place.

Increased choice however also presents a paradox. Too much choice can actually overwhelm us and cause us not to buy anything at all. This is another advantage of presenting products in isolation at the end of an aisle as opposed to down the aisle where the full selection of alternatives is available.

A case study conducted by the American consumer psychologist Sheena Iyengar clearly demonstrates this paradox of choice. In this experiment the researchers manipulated the number of varieties of jam available to shoppers. When six varieties were made available only 40% of shoppers stopped to browse compared to 60% when 24 varieties were on offer.

So, increased choice is attractive. However, when we come to look at the number of shoppers who went on to buy some jam, in the first scenario 45% of those stopping to browse made a selection vs only 2% when the full 24 varieties were available.

The experiment also raises an important issue about supermarket shopping which are the stages of the shopping process. When we are in a supermarket there is an assumption that we are always in the process of buying things. However this is not always the case. Actually as much as 80% of the time we spend in a supermarket is not associated with us engaging with and buying products. As is clearly evident in in-store eye tracking exercises, most of our time is spent moving about the store from one shopping event to the next. When we’re doing this we tend to switch off, rather like driving a car, and we go with the flow, following a route of least resistance, which is why we tend to follow the wide perimeter race track.

Eye tracking studies show us how people spend their time in the supermarket

So to make a sale the retailer and product manufacturer first need to capture our attention and get us to slow down, stop and look at the products on sale.

Once they’ve captured our attention we become shoppers, rather than just passing traffic. The process of shopping then moves on to the next stage, closing the sale.

In closing the sale the jam experiment demonstrates one of the limitations of the human brain with respect of decision making. That is that the ‘Pre-frontal Cortex’, the area of our brains which is concerned with weighing up odds and making considered decisions, is only capable of handling around seven pieces of information at any one time. Overwhelm the Prefrontal Cortex and you scupper the decision making process meaning that as a shopper you are more likely to give up and default to a natural risk-averse behavior of withdrawing from the task at hand.

In situations where we are confronted with a complex decision we have two strategies available to us. Firstly we can take a pen and paper and assist the Prefrontal Cortex in the process of making a rational decision. In a supermarket environment this is not very likely for two reasons, firstly we don’t have the time to spend on such an exercise and secondly the exercise does not seem worthwhile given its relatively inconsequential outcome. Does it really matter to you that much which jam you buy?

A second course of action is to bypass the Prefrontal Cortex and rely instead more on our “gut instincts”. This process employs different parts of the brain, including the Nucleus Accumbens and the Insula which act as a subconscious barometer of a situation, taking in a wealth of sensory information and processing it to give us a guide to our actions. We are not consciously aware of the rationale behind the balancing act between the Nucleus Accumbens and the Insula, the former of which provides positive cues and the latter tempering these with negative signals, we are only aware of the outcome and the feeling or drive that they provide. How often have you been questioned about a decision you have made and been unable to give a reason behind it other than to reply “it just felt right!”?

The Prefrontal Cortex, Nucleus Accumbens and Insula in the human brain

So relying on our gut instincts and employing the Nucleus Accumbens and Insula would seem like a good tactic. Unfortunately this decision making system, in evolutionary terms, is very old and is something we share with many other species. It is designed to cope with relatively straightforward situations such as choosing a berry that is good to eat or fighting or fleeing from attack. In the complex world that we have built around us this subconscious and emotional decision making tool can often prove flawed and susceptible to being hoodwinked. Consequently, whether they understand the science behind it or not retailers and manufacturers alike have developed an arsenal of tricks which capitalize on its limitations.

The Nucleus Accumbens and Insula are adept at parsing a situation and identifying positive and negative elements. Emphasize the positive over the negative and the Nucleus Accumbens is more likely to win over the Insula giving us a “green light” to take a certain course of action.

This has been very well demonstrated by the Nobel Prize winning Psychologist Daniel Kahneman in his work on decision making which has led to his development of Prospect Theory. To demonstrate this let’s take one of Kahneman’s experiments.

A sample of people is presented with one of two scenarios in which they are required to make a decision. Both scenarios are identical in terms of the odds associated with the choices they ask people to make and the potential outcomes. However they are presented in subtly different ways.

In Scenario 1 600 people have contracted a potentially fatal disease for which there are two possible cures. Cure A is guaranteed to save 200 people whilst Cure B has a 33% chance of saving everybody but a 66% chance that nobody will be saved. The decision maker only has funds for one of the two cures. Which would you choose?

Again in Scenario 2 the disease threatens the lives of 600 people. Cure A will result in 400 people dying (this is the same as 200 surviving in Scenario 1) whilst Cure B has a 33% chance of nobody dying but a 66% chance of everybody dying (again the same as Scenario 1 but with the emphasis on death rather than survival) The decision maker only has funds for one of the two cures. Which would you choose?

Obviously the information in brackets is not provided to the respondents.

What is interesting here is that despite the probabilities and outcomes of both scenarios being the same, the number of people choosing Cure A over Cure B differs markedly between the two scenarios.

Daniel Kahneman’s classic Prospect Theory experiment

In Scenario 1 where the number of lives saved by each cure is emphasized, far more people will opt for Cure A since it guarantees some people will survive.

However, in Scenario 2 where the fatalities associated with Cure A are emphasized Cure B will be opted for more frequently since the 33% possibility of saving everyone over allowing 400 people to die is more compelling.

Whilst on the face of it the experiment above has little to do with the decisions we make in the supermarket, it does demonstrate the powers of persuasion that can be tapped into through the subtle framing of an offer on the supermarket shelf.

One way in which retailers subtly frame a product proposition is to play to our perceptions of scarcity. In other words by making the downside of not buying a product seem more detrimental or in a sense making the consequential fatalities more overt.

This can be achieved by imposing a limit on the time window in which the offer is available or a limit in terms of how many products people can buy, thereby giving a sense of scarcity. The effect of such a promotion can be demonstrated in a readily replicable experiment at a supermarket shelf.

First we set up a promotional display which communicates a modest price reduction on a product such as baked beans, this being selected since most people buy them and they can be stored so there is no reason in principle why people should not buy multiple items.

Counting the number of shoppers who stop and buy from the display and the number of items that they buy will reveal that the display is largely ignored.

However, if we then alter the promotion, so that the discounted price remains the same but a sign is presented limiting the number of cans to five per shopper, suddenly we see far more shoppers both stopping to buy the beans and purchasing multiple cans.

The simple act of limiting the number of cans per shopper has increased perceptions of scarcity and made the consequences of not purchasing seem more significant.

BOGOF’s appeal to our Nucleus Accumbens

Other promotional techniques also use subtle psychology to prompt more shoppers to buy products. For instance the commonly used Buy One Get One Free (BOGOF) promotion makes us feel that there is more to gain and less to lose if we select the product. In some cases this is a fair deal so long as we don’t end up throwing away the excess because we don’t need it.

However, it isn’t simply a case of the retailer giving away products. By employing a BOGOF effectively, and retailers have a lot of experience and data that they can analyze associated with this practice, not only do BOGOF’s result in shifting twice the number of items but they also prompt more people to buy them. This uplift in the volumes of items sold has two benefits, firstly, for items that can be stored in the kitchen cupboard the promotion ensures that the retailer will capture a larger volume of the overall market for that product over a longer time period since people are less likely to subsequently buy more of that product on another occasion at another competing store. Secondly, the promotion enables both the retailer and product manufacturer to take advantage of economies of scale both in terms of production and distribution since with an increased volume of the product being sold through any one store the unit cost of supplying the product is reduced and as such although the unit price of an item to the shopper is reduced the profit margins associated with it if managed effectively can be inflated.

But promotions aren’t the only way to get us to buy things, so now let’s take a step backwards in the process of shopping. Before retailers can close a sale they need to get us to stop and look at the products on the shelf. To achieve this there is a need to attract our attention. Considering the supermarket is one of the most complex environments that most of us encounter on a day to day basis (30,000 products spread across a similar amount of square footage of floor space) and shoppers are moving through the environment at a rate of about 1m / sec, this is no mean feat. We tend to block out the visual noise of most of the products in a supermarket and our walking speed means that anything we pass has a very limited opportunity to attract our attention.

At most we can read and comprehend between three and six words per second, so word based signs are of limited value in attracting attention and retailers and manufacturers need to rely on more basic approaches such as the use of shapes and colors.

Firstly let’s think about color. Have you ever stopped to wonder why promotional labels and sale signs tend to be red?

There are actually some very good reasons for this.

To begin with we must consider the back wall of the human eye responsible for the detection of light, the Retina. This contains thousands of photo receptor cells called Rods and Cones. Rod cells are receptive to differences in light intensity, dark and light, and allow us to determine shape and form, but do not allow us to perceive color. The detection of color is down to the Cones. There are three different types of Cones in the human eye, each of which is responsible for the detection of light at different wave lengths, or colors. Some Cones are sensitive to light with a short wave length (blue light), others react to light with a medium wave length (green light) and finally there are Cones sensitive to light with a long wave length (red light). The distribution of these three types of Cones is however not even across the Retina. In the centre of the Retina which translates to the centre of our field of vision where our visual perception is at its sharpest, there are no blue Cones at all and red Cones dominate. As a result we are biologically tuned to see things which are red in sharper focus than we are able to see things that are blue. Red signs in a supermarket are therefore more readily visible than those which use other colors. But this phenomenon is not a chance occurrence.

If we consider the colors which dominate in nature we find that of all the visible colors and hues within the spectrum it is reds and greens that dominate with a notable absence of blues. Our eyes in effect have evolved to concentrate on colors with the greatest significance to us in our interactions with our environment. Furthermore, in nature reds are frequently associated with things we need to pay attention to; many fruits for example are red in color as are potentially dangerous signals such as the gaping jaws of a wild animal. Red therefore is a highly significant color to us and so there is little wonder that the area of our Retina responsible for perceiving our environment in the highest resolution is awash with cells adapted to perceive light at the red end of the spectrum.

Now let’s consider shape. By nature we are tuned to be inquisitive towards novel shapes, it is part of our survival mechanism that if an unusual shape appears in our environment we focus our attention on it in order to work out if it is good or bad.

The use of novel shapes combined with conspicuous colors is therefore pivotal in the design of the product packaging that we find on a supermarket shelf. These factors make products stand out amongst all the other jars, tins, packets and bottles in an aisle and attract our attention, causing us to slow down and stop for a closer look.

Many successful products have developed highly distinctive packaging based on shape and color alone. Can you indentify the products below which have had all the text removed based solely on the shape and color of their packaging?

For the product manufacturer the supermarket aisle is a constant battleground where products vie for our attention through the use of shape and color. No sooner does a manufacturer hit upon a winning design than another comes along to upset the apple cart. A good recent example is the introduction of black bleach bottles in the household cleaning aisle.

The shapes and colors used for different types of products in different aisles also provide us with more general cues which help us navigate our way around the supermarket. Rather like the picture (left) where the combination of black blobs in total provide us with an image of a Dalmatian dog so the combinations of packaging shapes and colors in a supermarket aisle signal to us which aisle we are in. This is perhaps at its most pronounced for ketchup where a huge bank of red bottles often referred to in the business as “The Red Wall” tells us exactly what is down that aisle.

But attracting our attention and converting us from a passing visitor to a shopper is only one part of the process. Once the retailer has a captive audience they then need to close the sale.

In closing the sale, packaging must also communicate to us something of relevance that allows us to determine if the product is what we want. So whilst for instance a red milk bottle may stand out extremely well and attract our attention it is unlikely to close the sale since in the context of milk red packaging does not give us the right signals about the product it contains.

We don’t on the whole tend to spend very long in selecting a product once we are standing in front of a supermarket shelf, a matter of seconds is not uncommon and certainly more than a minute is unusual. Given again the speed with which we are able to read and comprehend text this does not mean there is much time to read a lot of detailed product descriptions on labels; again the use of colors, imagery and carefully chosen words which act as metaphors for more detailed and compelling concepts are the order of the day. There is an entire science called Semiotics devoted to the study of the cultural meaning of signs, symbols and colors; and packaging designers tap into this in a big way to communicate by the most effective means possible the reasons why we should buy a product.

Let’s take another example, this time from the cheese aisle. Cheese is a product where connotations of quality are strongly linked to a sense of artisan craftsmanship and heritage. So the packaging design for the cheese shown below uses a number of devices to convey this impression of the product to the shopper. The use of a burgundy red color has connotations with something regal and perhaps special and this is further enhanced by the use of gold. The name itself also acts as a metaphor for heritage and perhaps expertise which has gone into its manufacture.

Our considerations when buying products in a supermarket will inevitably vary according to the nature of the product we are buying. As such the design elements used in packaging for different types of products vary to reflect this.

As our society changes, cultural evolution also impacts on the way we buy our food. For example In recent years there has been an enormous uplift in our general concerns over the role of diet in ensuring our personal health and wellbeing. Partly as a result of legislation and also moves on the part of the supermarkets to be seen to share in these concerns we have seen an increase in the availability and detail provided on packaging relating to ingredients and nutritional value.

However, whilst a minority of shoppers for whom these issues are paramount may well use this information to inform their choices at the supermarket shelf and spend a longer time making those decisions as a result, the majority of us, owing to time considerations and a lack of inclination continue to make rapid and subconscious decisions based on the semiotic metaphors contained within packaging designs. This is not to say that health issues do not have more influence over our purchase decisions than they used to, just that aspects such as nutritional value have a stronger influence over our Nucleus Accumbens and Insula than in the past.

So, the way we approach supermarket shopping is deeply subconscious for many of us and supermarkets and the manufacturers of products they supply are tuned into this and play to it.