New research finds a link between poverty and poor decision making. The findings may explain why poor people sometimes make bad choices that continue their hardship.      Earlier studies have found the poor less likely to escape poverty. But there has been little research on why the poor make decisions that make their lives harder. Until recently, it was economists who studied poverty, not psychologists. Eldar Shafir, a psychologist in Princeton University says now scientists from both fields work together. Mr. Shafir and his team did two experiments. One took place at a shopping center in New Jersey.  Another was carried out among sugar cane farmers in rural India.       The New Jersey experiment involved individuals with low paying jobs and others belonged to the middle class. All the volunteers were asked what they would do if their cars needed repairs.      The volunteers were given two imaginary situations. In the first, the car repairs cost $ 150.  In the second,  $ 1,500.      "And what we found is that the poor and the rich performed equally well on almost all the tests. "       Not so when the researchers raised the repair costs to $ 1,500.      "Now the poor performed significantly worse. " The poorer lost about 13 IQ points on average. This is about the loss experienced when a person has not slept for one night.      The scientists then wondered if the same person reacted differently when he was rich and when he was poor. The Indian sugar cane farmers earn most of their money once a year, when the harvest comes in. But the money often does not last through the year.     "So they find themselves basically rich after the harvest when the income comes in and poor just before the harvest.      The researchers gave them tests similar to the ones taken by the people in New Jersey. They tested the Indian farmers before the harvest and after.      And the results were much the same as with the mall shoppers.      "They performed much more slowly and with many more mistakes when they were poorer than when they were richer. "      Mr. Shafir says the results support 50 years of research that shows all humans have limited mental power to deal with things in life.      "And so the insight here is that, having not enough of something in a way makes it harder to make good decisions for everything else. " What is true about earlier studies?    (_)
They were done by economists and psychologists. They found it hard for poor people to become rich. They explained why poor people made poor decisions. They showed the poor people cared less about their health.