The idea that dreaming is a simulation of the waking world is currently becoming

a far more widely shared and accepted view among dream researchers. Several

philosophers, psychologists, and neuroscientists have recently characterized

dreaming in terms of virtual reality, immersive spatiotemporal simulation, or realistic

and useful world simulation. Thus, the conception of dreaming as a simulated

world now unifies definitions of the basic nature of dreaming within dream and

consciousness research. This novel concept of dreaming has consequently led to

the idea that social interactions in dreams, known to be a universal and abundant

feature of human dream content, can best be characterized as a simulation of human

social reality, simulating the social skills, bonds, interactions, and networks

that we engage in during our waking lives. Yet this tempting idea has never before

been formulated into a clear and empirically testable theory of dreaming.

Here we show that a testable Social Simulation Theory (SST) of dreaming can be

formulated, from which empirical predictions can be derived. Some of the predictions

can gain initial support by relying on already existing data in the literature,

but many more remain to be tested by further research. We argue that the SST

should be tested by directly contrasting its predictions with the major competing

theories on the nature and function of dreaming, such as the Continuity Hypothesis

(CH) and the Threat Simulation Theory (TST). These three major theories

of dreaming make differing predictions as to the quality and the quantity of social

simulations in dreams. We will outline the first steps towards a theory-and-hypothesis-

driven research program in dream research that treats dreaming as a simulated

world in general and as a social simulation in particular. By following this

research program it will be possible to find out whether dreaming is a relatively

unselective and thus probably non-functional simulation of the waking world (CH),

a simulation primarily specialized in the simulation of dangerous and threatening

events that present important challenges for our survival and prosperity (TST), or

whether it is a simulation primarily specialized in training the social skills and

bonds most important for us humans as a social species (SST). Whatever the evidence

for or against the specific theories turn out to be, in any case the conception

of dreaming as a simulated world has already proved to be a fruitful theoretical

approach to understanding the nature of dreaming and consciousness.