How Credit Cards Affect Our Brains

It’s been known for decades that credit cards encourage spending. But why that happens still isn’t entirely clear. New research offers some fresh insight into the causes—and how consumers might be manipulated in an increasingly cashless society.

Research on credit-card spending has tended toward the explanation that delaying payment removes a barrier to purchases in shoppers’ minds. A study published in February in Scientific Reports found evidence of another kind of trigger. Differences it found in brain activity between shoppers planning to use a credit card and those planning to buy with cash indicate that buying on credit doesn’t just ease shoppers’ inhibitions, it actively encourages purchases, the researchers say.

The upshot: When people are shopping with credit cards and see a product they like, the neural network in the brain that produces a sensation of reward perks up, which seems to create a craving to spend, says Sachin Banker, assistant professor at the University of Utah, who worked on the study as a Ph.D. student at the MIT Sloan School of Management.

“You’re basically feeling more reward when you shop with credit cards,” he says. “We don’t see that with cash. It was actually a very stark difference.”

Researchers used a form of magnetic resonance imaging to measure the brain activity of the study subjects as they participated in a shopping exercise. Each participant was shown a total of 84 everyday products over the course of three sessions and was asked whether they would buy each product at the stated price. Half the products were offered for purchase by credit card and half for purchase with cash. None of the products cost more than $50.

The differences in the shoppers’ brain activity support the hypothesis that after repeated credit-card purchases over time the brain learns to anticipate the rewards of credit-card shopping, according to the report. And that suggests that consumers could be conditioned to spend through the use of various sensory rewards in new payment systems, Dr. Banker says. For instance, with digital payments the use of particular sounds or vibrations on your smartphone when you make certain purchases but not others could, over time, teach your brain to anticipate rewards for buying specific products while you’re shopping.

Dr. Banker adds that further research could be done to see if the study’s theories hold true at higher prices. It also could study consumers who tend to overuse or misuse credit cards, to understand further why they act as they do. This study focused on people who mostly paid on time and used credit cards appropriately. Understanding brain patterns for other types of consumers could help lead to solutions that attempt to pre-empt harmful spending behaviour, Dr. Banker says.

Millennial women’s wealth is outpacing men’s as a new generation inherits and grows their assets at a wider scale than ever before, according to RBC Wealth Management.

In a survey of roughly 2,000 men and women with at least $1 million in investable assets, millennial women respondents had an average of $4.6 million, compared with $3.8 million for women of all age groups and $4.5 million for all men.

Inheritance is one part of the picture, as baby boomers are expected to transfer $124 trillion to the next generation, but so is the progress millennial women have made in the world of business, investment and lucrative professional careers as they close the gap with men.

“Millennial women are catching up, or have outpaced the males as far as their wealth building,” said Angie O’Leary, head of wealth strategies at RBC. “We know that’s coming from a more diversified set of investments, such as entrepreneurship, real estate and of course, investments [in financial markets].”

Millennial women, now in their 30s and 40s, tend to differ from earlier generations of women more than they do from men in terms of their source of wealth. While investments were the largest driver of wealth across all categories, millennial women cited business ownership, innovation, and executive roles far more than Gen X or boomer women.

More than 60% of millennial women cited business ownership and more than 40% mentioned executive roles, but neither exceeded 22% for either Gen Xers and Boomers. Younger women also grew their fortunes from professional sports or arts 39% of the time, compared with just 6% and 1% for Gen Xers and Boomers, respectively.

In terms of inheritance, the gap between generations was smaller. About 37% of men and 35% of women cited family money as a source of wealth overall, breaking down to 44% of millennials, 30% of Gen X and 33% of boomer women.

With women controlling so much wealth, their spending and investments as a group are evolving and extending into areas previously considered stereotypically male such as real estate, cars and watches, O’Leary said. “Women are starting to look a lot like their male counterparts when it comes to investments, real estate, philanthropy,” she said. “That’s a really interesting emerging female economy.”

In real estate, for example, single women made up 20% of home buyers in 2024 up from 11% in 1981, when the National Association of Realtors began tracking the data. By contrast, single men make up 8% of the market and have never exceeded 10%, according to NAR.

While men and women shared largely similar priorities overall in terms of well-being, relationships, legacy and personal drive, younger generations of women were successively more likely to value drive and personal power, and successively less likely to rank relationships and social bonds—though that could also be a function of age and stage of life.

“This generational shift suggests evolving societal norms and responsibilities, where younger women seek personal achievements, while older cohorts value nurturing connections and community stability, affecting their financial and lifestyle choices,” the report said.

How Credit Cards Affect Our Brains

Buying with plastic doesn’t just eliminate a barrier to buying. It actively encourages purchases.

A survey of people with at least $1 million in investable assets found women in their 30s and 40s look nothing like older generations in terms of assets and priorities