December 8, 2012

How stores trick our senses to make us buy more (Part 1 of 5: Taste)

On the first day of Christmas my true love gave to me...

...a bunch of crap I really didn't need.

With just sixteen shopping days until Christmas, it's easy to get roped into buying things we might not actually have on our gift list.

Most times, we're conscious of our impulse purchases—there's a great sale on this! I'll use that later!

But sometimes reasons for our frivolous purchases are not so obvious to us. Don't feel too bad—store chains actually hire researchers to study our shopping patterns and take advantage of our weaknesses.

Our brains are endlessly fascinatingly organs—but sometimes they betray us. The following is the first post in a five-part series on how stores trick our senses into shelling out more money than we may intend.


Did you ever take the Pepsi Challenge?

For those unfamiliar (or living under a rock), the Pepsi Challenge was a campaign started by Pepsi back in the 1970s where Coca-Cola was pitted against Pepsi in a blind taste test by consumers.

When it was revealed that most Americans chose Pepsi over Coca-Cola, sales skyrocketed.

How they tricks us: We consumers like brands, and we're loyal to them.

It make sense, right? If you love your old Chevy but are in the market for a new car, you'll probably stick to the same make. It's familiar, and it didn't let you down.

In 2004, Dr. Read Montague of the Baylor College of Medicine tested the Pepsi Challenge on people while their brains were imagined in an fMRI machine.

Among the volunteers, more than half of them, much like the national polls, claimed to prefer Pepsi.

Their enjoyment was confirmed via fMRI. Compared to Coca-Cola, activity was greater in the ventral putamen—a region associated with reward—when volunteers sipped on Pepsi.

The study then took a surprising twist when Dr. Montague conducted his second experiment. This time, the volunteers were told whether they'd be sampling Coke or Pepsi before they took a sip.

Strangely, 75% of participants suddenly claimed to prefer Coke.

Furthermore, fMRI scans showed activity in the medial prefrontal cortex—associated with higher thinking and decision-making—in addition to the ventral putamen. Now, it seemed, their brains were locked in a battle of rational thinking versus pleasurable feeling.

Why, exactly, did this happen? Montague reasoned that, suddenly, Coca-Cola's brand—its logo, color, history, the memorable ads and childhood recollections—beat out young, newfangled, inexperienced Pepsi.

One's biased, emotional link with a brand, it appears, can trump our natural, unbiased preferences.

Forget a blind taste test. If you went by brand alone, which cookies (below) would you buy without thinking?

Now guess which costs more...?

Check back later this week for "How stores trick our senses to make us buy more (Part 2 of 5: Sight)."

McClure SM, Li J, Tomlin D, Cypert KS, Montague LM, & Montague PR (2004). Neural correlates of behavioral preference for culturally familiar drinks. Neuron, 44 (2), 379-87 PMID: 15473974


  1. As always, it's more complex and likely cortical activities have little effect.

    It appears:
    - Behavior is triggered and directed, unconsciously in 150 ms
    - This is a continual feedback process

    Best to look at brain stem for behavioral drivers.

    1. The brainstem is certainly involved in some basic functions, but I'd argue that the cortex is more important in this complex behavior.

  2. The taste of the food also will have a memory in their brain. When they were told what they will taste they have their memory of what soda they use to like more. Maybe they liked how coke use to taste and did not enjoy the way pepsi tasted. Now Pepsi and Coke could have changed their taste and the new taste is only tasted when their old taste memory is not brought up. So the difference in what soda was preferred could also be influenced by the taste memory.
    -Bryan Hill

    1. A good thought, but remember—the researchers knew which soda each participant preferred, and the majority of participants' brains showed that they derived more pleasure from Pepsi than Coke (via the fMRI showing ventral putamen activity).

      Over 50% of the participants entered the experiment saying they preferred Pepsi, but when they were told they'd be drinking Coke in the second experiment, 75% of the same participants said they preferred Coke!


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