What are dependent and independent variables in the following?
Prolonged stress is unpleasant and leads people to seek ways to reduce stress. Smoking, drinking, and drug use is ways in which people self-medicate to reduce stress.
The number of cigarettes smoked, drugs taken or drinks imbibed would be the dependent variable in a study of stress and use of smoking, drinking or drug-taking. In fact there is a difference between personality factors, some being more resilient and less likely to turn to substances to relieve stress.
Although job stress has a positive and statistically significant impact on smoking intensity, this is truer for light smokers, while it has a positive and significant impact on alcohol consumption mainly for heavy drinkers according to a recent Canadian study. In short, it is not a simple case of finding that if you increase a person's stress, they will use substances more.
I.V.: Stress (Levels: none, moderate, strong)
O.D.: Randomly assign participants to 3 conditions. In the first condition, have them watch a video of 9/11 footage and then count the number of cigarettes smoked in the next hour. In the second condition, show subjects pictures of 9/11. In the last condition, show subjects pictures of a birthday party.
O.D. The number of cigarettes smoked in one hour following trial conditions.