Dirty Walls – An evolutionary theory to explain the dream function

Abstract

One set of theories defer to Freud (1900) who said that the motivation for all dream content was wish-fulfilment albeit that this becomes more and more distorted as we grow older. Psychologists have also recognised similarities between some aspects of dreams and the output of computers during data configuration. (Crick, F., Mitchison, G. 1983. Henn evin, E., Leconte, P. 1971) Another theory proposes that repeated negative experiences in dreams help us to cope with adverse experiences in real life. (Revonsuo, A. et al. 2003) Alternatively, dreams may be just a random by-product of some other process. The natural world is full of these. One can easily see why, for instance, a caterpillar has evolved a green skin to hide from predators in the green tree where it lives. The fact that the tree has green leaves does not need an evolutionary explanation, however. It’s simply because the photosynthesising molecule, chlorophyll, happens to be green. In biology, this is known as a spandrel. There may be no evidence to prove that dreams are anything other than a spandrel – or some incidental by-product of the immensely complex processing of data in the brain but, if that is the case, why do we have to ‘experience’ them at all? One would think that we have more than enough to experience in tasting, smelling, feeling, hearing, seeing, remembering and recalling in our waking life. Given the extreme precariousness of the lives of our hunter gatherer ancestors and that of our pre-human forebears, our brains must have surely evolved every means possible of ‘thinking’ our way out of danger, just as our legs have evolved to meet our life or death hunting and escaping needs. Is it possible that dreams could have played an important role in our efforts to survive and thrive and continue to do so? Even if we can’t yet prove that dreams have an independently useful function, surely the fabulously exotic experience of dreaming and the degree of mystery dreams create in our lives must be more important than a mere by-product of the mechanisms of our body. And if there is a reason for dreams, we should try to find out what that might be.