Animal social behavior emerges from interactions among individuals, therefore, it is important to understand both the mechanisms that shape interactions and their consequences. Because most animals need to be in proximity to interact, individual differences in animal movements are especially important for determining who interacts with whom. Furthermore, the environment can shape the ways in which animals interact, for example by impacting their movement patterns. Social interactions in turn determine population-level processes, such as information flow and disease transmission, which can impact fitness and shape the evolution of sociality. In this talk, I will examine various causes and consequences of social interactions with examples from social insects and birds using lab experiments, field observations, models, and social network analysis. Uncovering the causes and consequences of social interactions is essential for understanding the emergence of social behavior.