Whether you're a New Jersey mall rat or a farmer in India, being poor can sap your smarts. In fact, the mental energy required to make do with scarce resources taxes the brain so much that it can perpetuate the cycle of poverty, new research shows.
The findings, published in Friday's edition of the journal Science, indicate that an urgent need — making rent, getting money for food — tugs at the attention so much that it can reduce the brainpower of anyone who experiences it, regardless of innate intelligence or personality. As a result, many social
"I think it's a game changer," said Kathleen Vohs, a behavioral scientist at the University of Minnesota's Carlson School of Management, who wasn't involved with the study.
There's a widespread tendency to assume that poor people don't have money because they are lazy, unmotivated or just not that sharp, said study coauthor Sendhil Mullainathan, a behavioral economist at
"That's a broad narrative that's pretty common," Mullainathan said. "Our intuition was quite different: It's not that poor people are any different than rich people, but that being poor in itself has an effect."
The problem is that it's hard to devise experiments to test this, said Eric J. Johnson, a psychologist at the Columbia Business School who was not involved in the study.
"In general, you can't randomly assign people to be poor," Johnson said.
Instead, Mullainathan has studied some of the specific consequences of being poor. Last year, he and his colleagues published work in Science showing that when people are forced to focus on a pressing financial problem like a looming utility bill, they develop tunnel vision and ignore their long-term goals.
For this new paper, the researchers wanted to find out how those psychologically draining situations affected their overall brainpower.
To do so, Mullainathan and his colleagues performed two very different studies on two very different groups of people — shoppers in a New Jersey mall and sugar cane farmers in rural India.
The shoppers were divided into groups designated as rich or poor based on their incomes. The researchers prompted them to consider their financial situations by asking them how they would pay for an unexpected car repair.
For half the subjects, the hypothetical bill was $150, a relatively low amount. For the other half, it was $1,500 — enough to make a person of modest means do some mental arithmetic.
Then the shoppers took a spatial intelligence test and another that measured their ability to control their impulses. The rich did fine no matter what the repair cost. The poor did OK too when the bill was just $150. But when it was $1,500, their IQ test scores dropped by 13 points.
The researchers surmised that concern about the looming expense had sucked up their brainpower.
"Almost like a computer that has some other process running the background, poverty creates this nagging background process and that could itself have an effect on actual cognitive capacity," Mullainathan said.
To see whether the effect was universal, the researchers traveled to India and surveyed 464 sugar cane farmers before and after a harvest.
Sugar cane farmers get paid only once a year. One month before harvest time, cash is running low; one month after harvest, they're flush with funds.
The farmers took the spatial intelligence and a different kind of cognitive control test before and after harvest. When they were strapped for cash, they performed worse on the IQ test and took slightly longer to answer questions on the cognitive control test than they did when money wasn't a problem.
The drop was substantial, Mullainathan said — about 9 IQ points.
"It's just crazy," Mullainathan said. "It was the magnitude that really put me on my heels."
The research lends support to the idea that many behaviors linked to being poor — using less preventive healthcare, having higher obesity rates, being less attentive parents and making poor financial decisions — may be caused by poverty rather than the other way around.
"It makes you think about the way people behave completely differently," Mullainathan said.
Many programs designed to help the poor require tedious paperwork, inconvenient appointments and the need to make extra financial decisions. Such requirements may undermine their intended aims, Mullainathan said.
Time is a resource anyone can run out of, Johnson said, but there are ways to reduce the burdens, whether it's filling out financial aid forms in advance, sending out reminders for payments, or setting optimal default choices for selecting healthcare.
"Governments and other people should avoid putting cognitive taxes on people" whether they're rich or poor, he said. "Making choices easier is going to help everyone. "