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NEW YORK (MainStreet) — A low income is known to be associated with bad health, higher mortality and low education—that's horrible enough. And now new research published in the journal Science suggests the sheer strain of financial trouble siphons away enough mental power to cause a substantial drop in IQ.

The study, led by researchers Eldar Shafir and Sendhil Mullainathan, conducted two tests on vastly different people: shoppers in a New Jersey mall, and sugar cane farmers in India. In New Jersey, a sample of participants with incomes ranging from $20,000 - $70,000 were asked how they would fix a car requiring "X" number of repairs. The repair cost ranged from low to high. This first kind of problem solving served as a reminder about their financial situation. Then, participants were given IQ tasks, and here's what happened: the low income participants performed just as well as the more affluent when the X amount was low, around $150. But when the cost increased, the poor "performed significantly worse" than the rich, according to the study, suggesting the looming worry over money can affect cognition.

"In terms of working capacity—the number of things you juggle in your head—you have a limited capacity," says Shafir. He likens it to remembering a seven-digit number as an example: if you're struggling to remember it, you're not going to perform very well with another problem needing immediate attention. Likewise, if you're preoccupied with bills and always feel a need to keep an eye on every dollar spent, your mind might struggle with other tasks.

The second part of the study focused on Indian farmers who are only paid once a year, after harvest. Pre-harvest, they're very financially strained; afterwards they're not. The researchers conducted IQ tasks before and after the harvest, and found farmers did significantly worse on the tasks pre-harvest—a whole 13 IQ points lower, in fact, which is roughly equal to losing an entire night's sleep.

So it's not that poor people are less intelligent than the affluent, it's that their brains are more taxed. The study isn't measuring those in totally impoverished conditions, but those in financial strain—something many Americans are no doubt familiar with.

"The poor do quite well with the task at hand," says Shafir. But while they're focused on managing dollars and cents, the "less mind they have for other things."

It's more that their fluid intelligence—the way we make sense of abstract problems—is impeded when they're reminded of their money woes. And for those with little solvency, that can be every day. Cognition tax can spill over into other areas of life, from remembering to count calories for a diet or forgetting to take medication, says Shafir, who co-authored the book Scarcity: Why Having So Little Means So Much (Times Books, 2013) with Mullainathan.

This scarcity can also be described as stress, or as Shafir and Mullainathan wrote in the study, "that poverty captures attention, triggers intrusive thoughts, and reduces cognitive resources—could itself be described colloquially as 'stress': persistent mental engagement induced by some trigger."

Which is the scary thing about being poor. It's an impending shadow that's "on you and doesn't leave you alone," as Shafir puts it.

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So can this mental taxation impede personal success?

Everyone knows someone who works, or has worked, a crappy job while working on a dream project. Many famous people did it. John Hamm did set dressings for soft-core pornography to make money while he tried to make it as an actor. But those are exceptions to the rule, and not everyone can find the time to work on a pet project while struggling with other bills.

"The greatest intrinsic drivers for human behavior are autonomy, mastery and purpose," says Cynthia Ackrill, M.D. and stress expert. "Autonomy is naturally challenged in poverty. [It's] harder to have what you need to achieve mastery. And harder to hold to a purpose beyond surviving."

Indeed, it would be hard to master something with limited resources. A popular theory by journalist and best-selling author Malcolm Gladwell says it takes 10,000 hours to become an expert in a profession, particularly those that are thought-based. Someone who doesn't need to work as much to make ends meet would have more time to devote towards mastering a profession, while the poor person will continue to struggle to find the time and mental resources.

Unfortunately, there's apparently no way to increase cognitive capacity. We asked Shafir if meditation or something else would work, but there's no magic bullet, no X number of hours to put into Sudoku in order mentally to bolster the burden. Instead, Shafir said to create a kind of "protective, budgetary cockpit" where you'll want to put up safeguards.

"Do something about it for weeks to come, something that imposes a reminder," says Shafir, like setting up automatic bill payments and deposits to ease the stress of possibly forgetting to pay bills. Keeping reminders in your phone for simple things like taking medication could also help.

It also helps to keep the faith.

"The people who make it out usually have stories of remarkable faith in something- themselves, a dream, a spiritual/bigger picture," says Ackrill. "And they often had someone who helped them believe. They repeat their attention to this frequently, creating neural pathways that hold them on their path."

--Written by Craig Donofrio