Human relations can serve a variety of functions. They can offer comfort, caring, and socioemotional support, especially when a person is stressed or scared. They can help to satisfy physical needs and wants, such as those for nutrition, shelter, and thermoregulation. People can help one another learn about the world around them (the exterior environment) and about their selves (the interior environment). It is this guiding and learning function of social relations which is our focus as we examine, in this book, the topic of social referencing in infancy.