Human cooperation is an astonishing phenomenon, as only humans exhibit such immense scale, complexity, and frequency in working together with other people. In this dissertation, I investigate how... Show moreHuman cooperation is an astonishing phenomenon, as only humans exhibit such immense scale, complexity, and frequency in working together with other people. In this dissertation, I investigate how nonverbal communication between two individuals affects cooperative success as well as methodological challenges when examining this topic in laboratory settings. To answer these questions, the dissertation comprises four chapters presenting two theoretical and two methodological studies. In the first two chapters, I demonstrate the beneficial effect of face-to-face interactions on cooperation. I subsequently show that physiological synchrony emerges during social interactions and is positively associated with cooperative success. This finding suggests that physiological synchrony might be an underlying mechanism for the beneficial effect of face contact on cooperation. In the methodological studies, I place the tasks typically used to measure cooperation into the broader context of prosocial behavior. Furthermore, I address the statistical challenges inherent to measuring synchrony between interaction partners. The cardinal point of this dissertation is that interpersonal processes that we are not aware of play a fundamental role in how we behave towards other people. Addressing methodological challenges that come along with studying dyadic interactions will greatly advance our understanding of social phenomena that make us human so unique. Show less
