A psychologist is interested in the effect of peer pressure on risk-taking behaviors of college students. The psychologist designs an experiment to determine this effect where 200 students (who volunteer to serve as participants) are randomly placed in one of two situations. In each situation, five participants sit in a room with four other people. The four other people are actually confederates of the experimenter (i.e., they are part of the experiment), and their behavior is determined before the experiment begins. Half of the participants witness the four other people in the room leaning back in their chairs (a behavior that involves the minor risk of falling over backward in the chair). The other half of the participants also witness the four confederates leaning back in their chairs but are further encouraged by the confederates to exhibit the same behavior (e.g., they tell the subjects that leaning back is more comfortable, fun). The behavior of each participant is observed to determine whether they do or do not lean back in their chair during the experiment. For each group, the number of participants (out of five) who lean back in their chairs is recorded.

a. List any independent variables in this study and the levels of each one.

1. What is the dependent variable, and how is it being measured?
2. What type of experimental design is this (e.g., bivalent, multivalent, or factorial)?
3. Explain why an experiment typically has higher internal validity but lower external validity than other research methods.