In a study by Wells and Petty, students listened to a radio editorial advocating for a tuition increase while testing earphone headsets. The students were more likely to support higher tuition rates (i.e., to agree with the editorial) if they had been nodding their heads. This supports:
1) The effectiveness of earphone headsets in influencing opinions
2) The importance of nodding in agreement
3) The impact of radio editorials on student opinions
4) The correlation between head movements and agreement with opinions