Which statement about mediators is most accurate?

Which statement about mediators is most accurate?

• A. It predicts the direction of an effect without explaining the mechanism.
• B. It is always a biological variable.
• C. It is a synonym for a moderator.
• D. It explains how or why an effect occurs by transmitting influence from the independent variable to the dependent variable.

Answer: (D)

Mediator analysis focuses on how an effect is transmitted through an intermediate variable, revealing the mechanism by which an independent variable influences a dependent variable. The best statement captures that a mediator explains how or why an effect occurs by carrying the influence from the IV to the DV. In other words, the mediator provides the causal path that connects cause to outcome, not just whether there is a relationship or in what direction. This helps distinguish mediation from other ideas. It isn’t limited to biological variables—mediators can be psychological, behavioral, social, or situational factors. It isn’t the same as a moderator, which describes a variable that changes the strength or direction of an effect under different conditions. And it isn’t merely about predicting the direction of an effect without explaining the mechanism; mediation explicitly models the transmission process that produces the outcome. Example: Think of a stress-reduction program (IV) reducing anxiety (DV) through increasing coping skills (mediator). The program changes coping skills, and those improved skills, in turn, lower anxiety. The mediator explains the mechanism by which the program exerts its effect.

Mediator analysis focuses on how an effect is transmitted through an intermediate variable, revealing the mechanism by which an independent variable influences a dependent variable. The best statement captures that a mediator explains how or why an effect occurs by carrying the influence from the IV to the DV. In other words, the mediator provides the causal path that connects cause to outcome, not just whether there is a relationship or in what direction.

This helps distinguish mediation from other ideas. It isn’t limited to biological variables—mediators can be psychological, behavioral, social, or situational factors. It isn’t the same as a moderator, which describes a variable that changes the strength or direction of an effect under different conditions. And it isn’t merely about predicting the direction of an effect without explaining the mechanism; mediation explicitly models the transmission process that produces the outcome.

Example: Think of a stress-reduction program (IV) reducing anxiety (DV) through increasing coping skills (mediator). The program changes coping skills, and those improved skills, in turn, lower anxiety. The mediator explains the mechanism by which the program exerts its effect.