If I give you two glasses of wine and tell you that one costs $50 a bottle and the other $10 a bottle, which one are you more likely to say tastes better? As plenty of studies have shown, the $50 wine is probably going to win the taste test, and that’s true even if both glasses are really the same wine. A new brain imaging study shows that this is more than a matter of preference: Our brain is wired to fall for the trick.
Study volunteers were first shown bottles of wine with the prices clearly marked, and then given a small amount to drink while they were in an MRI scanner. For each wine, they were asked to rate the taste on a nine-point scale. The wine prices shown to the participants ranged between 3 to 18 euros (the equivalent of about $4 to $22), but in reality, all of the wine was the same and cost about $14.
As predicted, the volunteers rated the allegedly higher-priced wine as tasting better than the allegedly cheaper wine. The MRI scan showed that when those evaluations were made, two parts of the volunteers’ brains experienced greater activity—the medial pre-frontal cortex and the ventral striatum. That’s important because those two areas are especially involved in evaluating expectations and seeking rewards. When we see a higher price, our brain links the price to greater expectation of reward, which changes our perception—in this case, taste.
"Ultimately, the reward and motivation system plays a trick on us," said study co-author Liane Schmidt, post-doctoral fellow at the INSEAD graduate business school.
The researchers call the result the “marketing placebo effect” because of its similarity to the well-evidenced medical placebo effect. If someone thinks that a pill will alleviate their pain, there’s a high likelihood that it will even if the pill is nothing but sugar. The same sort of brain trick is playing out—an expectation of pain relief is linked to what we think we know about the pill, just like an expectation of better taste is linked to what we think we know about the wine.
Some of the most unbelievable (yet so believable) examples of this are scenarios in which people are given a few glasses of water to taste and rate, after being told the prices of the water along with explanations for why some are so expensive (“found only in remote, pristine mountain springs,” etc.). After falling for the trick, everyone is told that all of the water was really the same and it came right out of a faucet. (Here’s a classic example from the Penn and Teller show a few years ago.)
The same dynamic applies to any number of things we evaluate all the time where a difference in quality is subject to our perception. The takeaway: don't forget to keep some healthy skepticism at the ready, and remember that your brain is complicit in the trickery.
The study was published in the journal Scientific Reports.