Abstract
The "synchrony effect" is a phenomenon whereby individuals may have heightened endorphin levels when they perform in coordination with one another. In 2010, Cohen and colleagues found that endorphin levels, as measured by pain threshold, of twelve male rowers was higher after rowing in a team condition than when participating in the same workout in a solitary condition. However, Cohen et al.'s sample consisted of teammates. Given the role of endorphins in team bonding, this may have affected their results. The current study built upon Cohen's design but included a synchronized condition involving strangers, as well as one with teammates. Twelve male rowers trained for 45 minutes under two conditions: alone and in a group. Half of the sample completed the group session with teammates; the other half completed it with strangers. As per Cohen et al.'s study, endorphin levels were tested via blood pressure cuff pain threshold test taken immediately after both trials. A 2 (individual versus group) x 2 (teammate versus stranger) repeated measures ANOVA revealed a significant interaction (F (1, 10) = 560, p < .05). Individuals participating with their teammates showed a significantly higher synchrony effect than individuals participating with strangers. While the sample size was small, it appears that the endorphin release in a group setting may be influenced by the nature of the relationships among group members.
