Links between people form networks of connections. These social connections have always been important in society. Patterns of connections go hand in hand with the nature of peer influence involved. Families, power structures and other hierarchies lead to social networks with tree structures. Traditional social networks are constrained by time and space and form patterns known as Small Worlds. New social media have no such constraints and display patterns known as Scale-Free Networks. New technologies are fragmenting social networks by eliminating the need for interactions between people. A growing social problem is that traditional support networks are disappearing, as highlighted dramatically by instances of people dying alone.