As described in Chap. 2 , being connected to other people is a fundamental component of being human. Our sense of self—that is our experience of being a person in the world—is provided by and reinforced through our interactions with others from the moment we are born. Other people responding and reacting to us, recognizing us as fellow humans in the social world, are important contributors to mental health and well-being. In early life, we are surrounded by people to interact with, and this continues into adulthood. As we progress from school to work or university, our opportunities to meet new people and grow our social networks increase. For a period of time, family may become the major source of social interaction, until children grow up and set out on their own. In later life, while there is more time to participate in activities outside the home, health, economic resources, location, or living situation may all contribute to reduced opportunities for social interaction. However, engaging in social interaction either in person or remotely through phone, messaging or video-calling is essential for well-being.