What pattern would confirm the independent variable had the intended effect on participants in a study?

• A. A. Heart rate and conductance are higher before participating in the first phase.
• B. B. Heart rate and conductance are higher for participants sharing $120 versus those taking $30.
• C. C. Heart rate and conductance are higher for the stress group compared to the control group.
• D. D. Heart rate and conductance are higher for participants before the second phase.

Answer: (C)

To determine the impact of an independent variable on participants in a study, researchers look for clear differences between groups that have been exposed to different conditions or treatments. In this context, a higher heart rate and conductance in the stress group compared to the control group indicates that the manipulation of the independent variable, which is likely related to stress induction, has had a measurable physiological effect on the participants. This difference suggests that the stress condition is effectively causing heightened arousal or stress responses, thereby confirming that the independent variable had the intended effect.

The physiological measures of heart rate and conductance serve as indicators of the body's arousal level, which is a common way to assess the impact of stress or other psychological stimuli. Therefore, the observed differences between the groups demonstrate that the independent variable (the stress manipulation) was successful in eliciting the expected responses in participants.