Study finds poverty reduces IQ, perpetuates financial woes

LONDON — Poverty and the all- consuming fretting that comes with it require so much mental energy that the poor have little brain power left to devote to other areas of life, according to an international study.

The mental strain could be costing poor people up to 13 IQ points and means they are more likely to make mistakes and bad decisions that amplify and perpetuate their financial woes, researchers found.

“Our results suggest that when you are poor, money is not the only thing in short supply. Cognitive capacity is also stretched thin,” said Harvard economist Sendhil Mullainathan, part of the team that conducted the study. Theresultswere published Friday in Science.

The researchers studied dozens of people from two groups— shoppers at a mall in New Jersey and sugar cane farmers in rural India. The researchers from universities in North America and from Britain’s University of Warwick found that pressing financial worries had an effect on poor people’s ability to perform well in cognitive and logic tests.

Far from signaling that poor people are stupid, the results suggest those living on a tight budget have their effective brain power, or what the researchers called “mental bandwidth,” dramatically limited by the stress of making ends meet.

On average, someone weighed down by money woes showed a drop in cognitive function in one part of the study that was comparable to a 13- point dip in IQ and similar to the performance deficit expected from someone who has missed a night’s sleep.

Eldar Shafir, a Princeton University professor who worked on the research, said financial worries led to a reduced ability to make sound decisions.

“The poor are often highly effective at focusing on and dealing with pressing problems,” he said. “But they don’t have leftover bandwidth to devote to other tasks.

“So, if you live in poverty, you’re more error- prone, and errors cost you more dearly.”