LONDON, (Reuters) – 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 the findings of an international study published on Thursday. The mental strain could be costing poor people up to 13 IQ (intelligence quotient) 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 an international team that conducted the study.