来自《耶鲁大学开放课程：有关食物的心理学、生物学和政治学 第12集》

• 
  
  but you don't know if it's the weight that's causing it.
  但你不清楚这是否就是体重引起的
• 
  
  Let's say heavier people are more likely to be in poverty
  假设 越重的人越穷
• 
  
  which is the case,
  这是真实情况
• 
  
  and it could be that the poverty is causing the mortality
  那有可能是贫穷引起了死亡
• 
  
  rather than the weight itself,
  而不是体重本身
• 
  
  weight is just a marker of it or a correlate of it.
  体重不过是个指标或者相关物而已
• 
  
  That would be an example of a correlation
  这是相关性的一个例子
• 
  
  and one of the weaknesses in cross-sectional studies.
  也是横向研究的一个缺陷
• 
  
  I also mentioned this up curve over here that we
  我也说过 曲线这里的上翘
• 
  
  -as we discussed in class
  就如我们课上所说的
• 
  
  might be attributed,
  可能是因为
• 
  
  in fact, is from the way the studies go to cigarette smoking.
  其实就是烟草研究得出来的结果