Passage Three
When trying to understand why some people have trouble living within their means, we tend to blame factors such as high interest rates and irresponsible spending. Now researchers have found another possible factor to add to the list: a gene linked to credit-card debt.
Earlier work has shown that genetics plays a role in how we handle money. But a recent study was the first to show that a particular gene affects financial behavior outside the lab. Researchers at the University of California, San Diego, and the London School of Economics looked at genetic data and questionnaires already collected from more than 2,000 young adults aged 18 to 26 as part of the National Longitudinal Study of Adolescent Health. In particular, they looked at whether these young adults said they had any credit-card debt and what version of the MAOA gene they had.
Monoamine oxidase A (MAOA) (甲型单胺氧化酶) is an enzyme that breaks down the signaling chemicals called neuro-transmitters in the brain. Previous studies have linked the low-efficiency versions of the MAOA gene - the variants that cause less MAOA to be produced by brain cells - to impulsiveness.
In the new study, people with one “low” MAOA gene and one “high” MAOA gene reported having credit-card debt 7.8 percent more often than did people with two “high” versions, the researchers found, even when they controlled for factors such as education and socioeconomic status. For people with two “low” versions of the gene, that number jumped to 15.9 percent.
The researchers were surprised by the magnitude of the difference. “The effect is almost as big as financial literacy,” meaning people’ s ability to digest complicated financial information, says Jan-Emmanuel de Neve, an author of the study.
But, de Neve cautions, an individual’ s version of the MAOA gene does not predict whether he or she is carrying debt. The gene affects credit-card debt the way other genes have been found to play a role in breast cancer: a particular version of the gene increases risk, but many other genetic and environmental factors are important, too.
Questions 11-15 are based on Passage Three.
11. The recent study has found that __________.
A. credit-card debt is mainly attributed to high interest rates
B. reckless spending is a major cause of a person’ s debt
C. young adults tend to spend more money than they earn
D. whether we overspend or not is probably determined by a particular gene
12. What have earlier studies proved?
A. The way we deal with money is related to our genetic features.
B. A particular gene affects financial behavior outside the lab.
C. Adolescents’ genetic grouping affects their health.
D. Too much MAOA may cause someone to behave impulsively.
13. What does MAOA refer to?
A. A neuro-transmitter. B. A gene.
C. An enzyme. D. A brain cell.
14. What can we learn from Paragraph 4?
A. People with two different MAOA genes run a greater risk of carrying debt than those with two low MAOA genes.
B. How much MAOA can be produced by brain cells depends on what versions of MAOA genes a person has.
C. People with two high MAOA genes are less likely to make ends meet than those with two different MAOA genes.
D. How much MAOA can be produced by brain cells is related to how many MAOA genes a person has.
15. According to the last paragraph, what does de Neve want to clarify about their research findings?
A. Different genes play different roles: one type of gene can’ t take the place of other genes.
B. The same gene that affects credit-card debt may also increase the risk of breast cancer.
C. The low version of MAOA gene is bound to leave people heavily in debt.
D. The low version of MAOA gene alone may not necessarily result in overspending.
