Why You’re More Likely To Buy Something When Shopping On Your iPad

The “endowment effect,” which makes us overvalue items, is stronger on a touch screen.


People tend to increase the value of an item the moment they take ownership of it. Psychologists call this the “endowment effect.” It shows up even in trivial things, like coffee mugs or chocolate bars, that people just received in a lab setting. The slightly irrational new owners of these items want much more money for them than rational buyers are willing to pay. Monkeys do it, too. Evidently it’s evolutionary.


So strong is the endowment effect that we don’t have to physically own something for the effect to take hold. The mere suggestion of ownership is enough to get our guns going. One recent study found that people who touched an item felt an increased sense of ownership toward it. A follow-up study found that simply imagining touching an object produced the same possessive feeling.

That evidence has clear implications for consumers: toucher beware. Once you come into contact with something in a store, you might be more willing to buy it, since you already feel like you own it. Back in 2003, the Illinois attorney general went so far as to issue a warning to retailers who encouraged holiday shoppers to handle the merchandise, for just that reason.

Recently, Boston College researchers S. Adam Brasel and James Gips wondered whether the endowment effect might kick in when people buy things online, too. They were most curious about people who shop on tablets, since tablet users pinch, zoom, and tap on an item. In short, they touch it.


“The core thing that we’re starting to work on is this idea that the interfaces that people are using to access content can really fundamentally change the way we see that content,” Brasel tells Co.Design.

Brasel and Gips designed two experiments to test that idea. In the first, they brought test participants into a lab and let them roam around websites for two products: college sweatshirts and walking tours of New York City. The participants all sat at a computer but some of them used an old-school mouse to search, others a touchpad, and others touched the screen itself.

Image: Courtesy of S. Adam Brasel

After the participants chose a product, they told the researchers how much money they were willing to accept if someone else wanted to buy it from them. On average, people in the touch-screen condition wanted significantly more money (roughly $68) than people using the mouse ($47) or the touchpad ($44). Some form of the endowment effect had clearly occurred.

“The key thing we saw move in terms of our variables is this ‘willing to accept’ price,” says Brasel. “That’s actually a really good measure of this idea of implied ownership.”

A touchable screen isn’t the same as a tablet, though, so Brasel and Gips arranged a second experiment pitting an iPad against a touchpad laptop. Once again, test participants navigated the websites of fake products (this time a sweatshirt and a tent, to control for “touchability”). And once again, after making their choice they told the researchers how much money they would need to sell it. (Test participants used both devices and purchased both items over the course of the study, for balance.)


In the iPad condition, the endowment effect thrived. On average, test participants using the tablet wanted to sell their item for significantly more than those using the laptop (roughly $213 to $154). Pressing a finger against a digital image on a fake website in a laboratory–that’s all it took to make people feel like they owned an item, and to value it more as a result.

“I think our impulse levels might be a little harder to control when we’re tablet shopping than when we’re computer shopping,” says Brasel. “We’re just touching it. It’s right there. We already feel like we own it.” The work was published online this month in the Journal of Consumer Psychology.

Tablet-shopping advisory aside, site designers can learn some lessons from the research, too. In the first study, Brasel points out, test participants felt a little more attached to the sweatshirts than to the walking tours–likely because they’re a more “touchable” product. “Highlighting those tactile elements might be extremely effective for someone who’s using a direct-touch interface,” he says.

At least you know who’s to blame when you get a sweater again this Christmas.

About the author

Eric Jaffe is an editor at CityLab, where he writes about transportation, history, and behavioral science, among other topics, through the lens of urban life. He's also the author of The King's Best Highway (2010) and A Curious Madness (2014)