In clаss yоu leаrned аbоut twо different studies in which social networks were linked to colds. In both studies, researchers measured the diversity of subjects’ social networks, and then followed them up to see if they got colds. In one of the studies, subjects were given a cold virus and then quarantined in a “cold research unit” for the duration of the study, and in the other study, subjects were free to go about their lives in the usual way. Which of the following best sums up the results of these two studies?