Science Lesson: Smokers as workers

Smokers make poorer workers
Smokers perform worse at work than non-smokers, finds a study of US navy female service members published in Tobacco Control.

Smokers were also more likely to have a less than honourable discharge, to be demoted, to desert, and to earn less than their non-smoking colleagues, the study showed.

So says a March 28, 2007 press release about the study. The press release does not directly identify the study, the issue in which is published, or any of the scientists associated with it.

The press release does, at the end, indirectly raise some good questions. Does smoking cause people to be bad workers? Does being a bad worker cause someone to smoke? Are both of those the case? Is neither?

PS. A letter published in 1999 in that same journal carries the headline:

The United States navy attracts young women who smoke