Poverty itself harms a brain's ability to think well, thus making tasks that would help the poor more difficult, a new study finds. The study could lead to improved methods for helping those in poverty.
"Poverty itself reduces cognitive capacity ... because poverty-related concerns consume mental resources, leaving less for other tasks," researchers Anandi Mani, Sendhil Mullainathan, Eldar Shafir and Jiaying Zhao found in the study, "Poverty Impedes Cognitive Function," published in the Aug. 30 issue of the journal Science.
To reach their finding, the researchers conducted two separate experiments. In the first, they chose 400 people randomly at a New Jersey mall whose income varied from $20,000 to $70,000. The test subjects conducted tests of cognitive function and were asked how they would respond if their car needed a $150 repair or a $1,500 repair. While there was little difference for the $150 repair, those with less income demonstrated a significant drop in cognitive function when their brains were taxed by the $1,500 repair question.
The second part of the study looked at farmers in India. These farmers routinely go through a yearly cycle of poverty and wealth. After a harvest, they get about 60 percent of their yearly income in a lump sum. Most of the year, they live in poverty. The researchers found that the farmer's brains functioned better after the harvest when they had more money than the rest of the year.
The loss of cognitive function due to poverty is equivalent to about 13 IQ points, the research found.
The loss of cognitive function means that those in poverty will have more difficulty accomplishing tasks that will help them get out of poverty, such as getting additional education or training. It also increases the likelihood that they will engage in behaviors that cost them more money, such as forgetting to pay bills.
The decrease in cognitive function also means that poor people have fewer mental resources to pay attention to the needs of their children, such as helping them with their homework, and the needs of their marriage, which could explain why the poor are more likely to get divorced. Both a high divorce rate and lack of involvement in a child's education contribute to a cycle of poverty.
"When your bandwidth is loaded, in the case of the poor, you're just more likely to not notice things, you're more likely to not resist things you ought to resist, you're more likely to forget things, you're going to have less patience, less attention to devote to your children when they come back from school," Shafir said in an interview with The Atlantic Cities.
The direction of influence is clear, Shafir added. It is not the case the people with lower IQ are more likely to be poor, but the state of being poor that impacts the function of the brain.
Programs aimed at helping the poor, the research suggests, should think of ways to free up some of the "cognitive bandwidth" consumed by poverty. The poor may do better, for instance, if their income were directly deposited into their bank accounts weekly and their bills were directly withdrawn.
Shafir and Mullainathan coauthored a book on the topic, Scarcity: Why Having Too Little Means So Much, which will be published on Sept. 3.
Mani is a professor of economics ad University of Warwick, Coventry, U.K. Mullainathan is a professor of economics at Harvard University, Cambridge, Mass. Shafir is a professor of psychology at Princeton University, Princeton, N.J. And, Zhao is a professor of psychology at the University of British Columbia, Vancouver, British Columbia.