Does intelligence cause greater alcohol consumption? I just stumbled on a blog post that asserts that more intelligent people drink more than less intelligent people.

The author writes:


  Controlling for a large number of demographic variables, such as sex,
  race, ethnicity, religion, marital status, number of children,
  education, earnings, depression, satisfaction with life, frequency of
  socialization with friends, number of recent sex partners, childhood
  social class, mother's education, and father's education, more
  intelligent children grow up to drink more alcohol in the UK and the
  US.


The data presented reportedly comes from the National Child Development Study (NCDS) in the United Kingdom and the National Longitudinal Study of Adolescent Health (Add Health) data in the United States. However, the author does not cite a particular reference where such analyses are reported.

Furthermore, I also wonder about what the meaning of any association between intelligence and alcohol consumption would be after controlling for so many factors. In particular, mother's education, father's education, social class, and education together should predict a lot of variance in intelligence. 

Questions


What articles report the actual analyses mentioned in the blog post? Or what other articles summarise the relationship between intelligence and alcohol consumption?
What is the relationship between intelligence and alcohol when you don't control for other factors?
How does the relationship change between intelligence and alcohol consumption when you introduce some but not all of the covariates? In particular, which if any covariates modify the relationship between intelligence and alcohol consumption?
Taken in totality is it reasonable to assume that intelligence has a causal effect on alcohol consumption?
This is just the beginning of an answer, based on what I've read so far. I'm very keen to read other answers.

Resnick et al (1997)

@Yannis Rizos has pointed me to the article by Resnick et al (1997) based on the National Longitudinal Study of Adolescent Health.
The article reports data on 12118 adolescents drawn from grades 7 through 12.

The results suggested that "individual characteristics explained 7% of the variability in frequency of alcohol use". The only variable mentioned related to intelligence was lower grade point average. Specifically, lower grade point average was related to more frequent alcohol use. If anything, this suggests that the relationship between intelligence and alcohol use is negative. This result is obtained as part of a regression model controlling for some demographic factors. The bivariate relationship without covariates is not reported.

Of course, there are many limitations. First, this study concerns adolescent drinking, which may be a quite different phenomena to adult drinking. Second, while GPA correlates highly with intelligence, it is not intelligence.

References


Resnick, M.D., Bearman, P.S., Blum, R.W., Bauman, K.E., Harris, K.M., Jones, J., Tabor, J., Beuhring, T., Sieving, R.E., Shew, M. &amp; others (1997). Protecting adolescents from harm. JAMA: the journal of the American Medical Association, 278, 823-832. PDF