Jessica researches the influences on cigarette smoking among women. She finds a relationship between the independent variable “weight concern” and the dependent variable of “cigarette smoking.” Specifically, her research findings show that women with a strong desire to control their weight are more likely than women without that desire to smoke cigarettes. After adding a control variable of “body image” that measures how the women feel about their body size (underweight, about the right weight, overweight), Jessica concludes that body size causes a change in weight concern and a change in cigarette smoking behavior. When controlling for body image, the relationship between weight concern and cigarette smoking is no longer causal. Which criterion for causal explanations does Jessica address with this research?
Answer
1. time order
2. association
3. nonspuriousness
4. causal mechanism