The Relationship between IQ and Being a VegetarianA Southampton

The Relationship between IQ and Being a Vegetarian
A Southampton University team found that people who were vegetarians（素食主义者）by 30 had recorded five IQ points higher on average at the age of 10. Researchers said it could explain why people with a higher IQ were healthier as a vegetarian diet was linked to lower heart disease and obesity（肥胖）rates. The study of 8,179 people was reported in the British Medical Journal.
Twenty years after the IQ tests were carried out in 1970, 366 of the participants said they were vegetarians—although more than 100 reported eating either fish or chicken.
Men who were vegetarians had an IQ score of 106, compared with 101 for non-vegetarians ； while female vegetarians averaged 104, compared with 99 for non-vegetarians. There was no difference in the IQ scores between strict vegetarians and those who said they were vegetarians but reported eating fish or chicken.
Researchers said the findings were partly related to better education and higher class, but it remained statistically significant after adjusting for these factors.
Vegetarians were more likely to be female, to be of higher social class and to have higher academic or vocational qualifications than non-vegetarians. However, these differences were not reflected in their annual income, which was similar to that of non-vegetarians.
Lead researcher Catharine Gale said, “The findings that children with greater intelligence are more likely to report being vegetarians as adults, together with the evidence on the potential benefits of a vegetarian diet on heart health, may help to explain why a higher IQ in childhood or adolescence is linked with a reduced risk of coronary heart disease in adult life.”
But Dr.Frankie Phillips of the British Dietetic Association said, 【“It is like the chicken and egg, " Do people become vegetarians because they have a very high IQ or is it just that they are clever enough to be more aware of health issues?】
5.What does the underlined sentence in the last paragraph mean?
A、Intelligence is linked to not just being a vegetarian but many factors.
B、The rate of getting heart disease is linked to your lifestyle.
C、The link between a high IQ and being a vegetarian is still uncertain.
D、The link between a healthy heart and diet remains to be proved.
【正确答案】：C
【题目解析】：推理判断题。文章最后一句的意思是：人们成为素食者是因为他们智商高还是因 为他们足够聪明而更注意健康问题？由此可见Dr.Frankie Phillips认为素食和高智商的因果关系尚未明确，就像弄不清楚是因为有蛋才有鸡，还是因为有鸡才有蛋一样。故C项为该题正确答案。