There may be no Cartesian ghosts residing within the machinery of the brain, but still, something rather peculiar is going on in there, especially during the darkest hours of the night. As we sleep and our bodies cease to interact behaviourally with the surrounding physical world, our conscious experiences do not entirely disappear. On the contrary, during sleep we often find ourselves embodied and immersed in an experiential reality, an altered state of consciousness called dreaming. The Dream Self—the character with which we identify ourselves in the dream world, and from whose embodied perspective the dream world is experienced—is who I am in the dream world (Revonsuo 2005).
But we are not alone in this alternative reality—there are other apparently living, intelligent beings present, who seem to share this reality with us. We see and interact with realistic human characters in our dreams. Their behaviour and their very existence in the dream world seem to be autonomous. The dream people who I encounter within the dream seem to go about their own business: I cannot predict or control what they will say or do. Yet, they, too, are somehow produced by my own dreaming brain.
On the one hand, dreaming is a solipsistic experience: when we dream, we dream alone, and outsiders have no way of participating in our dream. Yet on the other hand, dreaming is an intensely social experience, even if the social contacts and interactions in the dream world are merely virtual. In this paper, we will explore the idea that dreaming is a simulated world, but not only a simulation of the physical world. It is equally or perhaps even more importantly a simulation of the social world. We will proceed in the following way:
First, we will argue that a remarkable convergence has gradually emerged in theories about the nature of dreaming. The field used to be a disunified battleground of directly opposing views on what dreams are, how exactly the concept of “dreaming” should be defined, and on the proper level of description and explanation for dreaming. Recently, the field has converged towards a more unified understanding of the basic nature of dreams. A widely shared conceptualization of dreaming now depicts it as the simulation of waking reality. We will briefly describe how this theoretical shift has taken place and where we currently are in the theoretical definition of dreaming. This theoretical development has paved the way for understanding the social nature of dreams in terms of social simulation.
Second, we will explore the nature of social dream simulation in more detail. In what sense can dreaming be taken as a simulation of our human social reality? How much and what types of social perception and interaction occur in dreams? This question can be broken down into a number of more detailed questions. We will try to answer some of these questions based on the already existing knowledge and empirical evidence about the social nature of dreams. Furthermore, we will try to formulate more clearly the questions that cannot yet be answered empirically due to the lack of appropriate data.
Third, we will review hypotheses that already address the question of the social nature of dreams or assign a social simulation function for dreams. Finally, we will outline some basic ideas of a Social Simulation Theory (SST) of dreaming that might offer some explanations for the social nature of dreams, or at least might produce well-defined, testable research questions concerning the possible functions of social dream simulations.
To describe and explain the social nature of dreams as social simulation, concepts borrowed from virtual reality technology may be applied, in this case to the social aspects of dreaming. One of these concepts is the notion of “avatar”: A simulated virtual human character who plays the role of a corresponding real human within a virtual reality. If dreams are virtual realities in the brain (Revonsuo 1995), then we ourselves within the dream world are avatars, and we interact with other avatars inside the simulated reality. Somehow, the dreaming brain is capable of creating credible, autonomous human simulations out of neural activities in the sleeping brain. A theory of dreaming as a social simulation should predict what kind of avatars are represented in our dreams, what types of interactions we engage in with them, and in particular, why it would be useful to simulate such avatars and interactions in our dreams—what functions, if any, do they serve for us.