Final answer:
Coccaro et al. involved college students in various studies, where they completed activities such as surveys, were fitted with penile plethysmographs for research on homophobia, participated in sessions on social capital and conflict transformation, and took on roles in a prisoners and guards experiment.
Step-by-step explanation:
Coccaro et al. conducted various studies involving college students participating in different types of activities or experiments. In one study, participants completed a 15-20 minute survey during class time, where incentives provided by the American Heart Association were offered. At another point, male students were given a scale to assess levels of homophobia and those with extreme scores participated in an experiment where they were fitted with a penile plethysmograph. Another activity involved students going through sessions on social capital and conflict transformation. Additionally, a notable study from Stanford University had students playing the roles of prisoners and guards. Across these studies, the participants engaged in a variety of tasks as part of Coccaro et al.'s research on human psychology and behavior.