For centuries, people have sought to explain not only what people dream about, but also why humans dream. In older times, dreams were used for prophecy. Later, they were used in the growing field of psychology.
But, until fairly recently, people only theorized about what dreams mean, and not why people themselves have evolved the capacity to dream.
This paper examines various theories that explain why human beings dream. The first part of the paper looks at the writing of Sigmund Freud regarding dreams as the royal road to the unconscious. Implicit in Freud's writings is the view that dreams evolved as humans were forced to sublimate their natural desires to live in society.
The paper then looks at the work of J. Allan Hobson, who saw dreams as a result of the natural physiological workings of the brain. In this body of research, Hobson meticulously matches the features of dreams to specific brain chemistry, offering a mechanical explanation for the function of the brain during sleep.
The last part examines the work of Owen Flanagan, who seeks a middle ground between dreams as the royal road to the unconsciousness and dreams as biochemistry Flanagan offers the view that dreams are merely evolutionary spandrels. However, though he is far from ascribing to dreams with the value which Freud placed on them, Flanagan also acknowledges that dreams may have values of self-expression.
Freud's key to the unconscious
For Freud, dreams were often responses to an experience the dreamer had during the previous day. An event or association of thoughts had led to a wish that had to be repressed because the dreamer found this wish socially-unacceptable. When the censor drifts off into sleep, the wish springs out to find expression (Kahn 158).
This expression, however, is rarely literal or realistic. Freud believed that the dream's latent content or concealed wishes were often distorted into its manifest content. This distorted manifest content is the part of the dream that the person remembers (Kahn 158-159).
These dreams, Freud maintained, were often disguised wishes that the dreamer hides, fearing that they are unacceptable. As such, dreams have much in common with neurosis, which Freud believed was caused by the repression of unacceptable sexual wishes. Freud's belief that dreams could be interpreted lay the foundations for his view that dreams were the key to unlocking neurosis as well (Kahn 157-158).
The key to the interpretation of dreams, on the other hand, lay in an interpreter's knowledge of universal symbols. For example, a king and queen in a dream were thought to represent the dreamer's parents. Many sexual symbols in particular - elongated, phallic symbols for the male organ and hollow, receptive objects for the female organ - could help an interpreter shed light on the latent content of dreams (Kahn 163-165).
Though Freud did say so directly, his belief that dreams are sublimated desires reveals an implicit belief that dreams evolved in some way to allow human beings to express socially-unacceptable desires. As part of the social contract, people agreed to give up certain rights to live in society. However, in the process, they also gave up the right to do many actions that Freud viewed as basic to human nature. This includes, for example, the free expression of sexual desire.
For decades, the interpretation of dreams formed the foundation for psychoanalysis. However, more modern scientific findings on sleep and dreams cast some doubt over Freud's thesis of dreams as wish fulfillment.
For example, an empirical study conducted by David Foulkes on children were showed that dreams involving the dreamer as an actor do not develop until quite late in childhood. Prior to this, younger children's REM sleep often involves static images. For Foulkes, this late development of narrative dreaming suggests a later development of reflective self-awareness as well (Foulkes 84-85).
If dreams were truly sublimated desires, however, then the young child would be more likely to dream of repressed wants - such as the cookie she was not allowed to eat before dinner or the toy he saw while at the supermarket with mommy. After all, children are taught to sublimate their desires at a younger age.
Biological research into sleep also shows that many mammals do, in fact, have dreams. Primate research involving gorillas who have been taught sign language often communicate about the images they see in their heads while they are asleep. While such accounts may be explained in Freudian terms as an animal's wish to be free, it also provides a startling challenge to the notion that humans evolved the capacity to dream as a social adaptation.
Finally, in the growing age of globalization, questions arise as to how truly "universal" Freud's symbols are. Recent challenges to the famous Rorschach inkblot test, for example, charge that Rorschach norms used to diagnose mental illness are unrepresentative of the United States population, leading to mistaken diagnoses. Test results for African-Americans, Native Americans, Native Alaskans and Hispanics differ markedly from the Rorschach norms.
In the same vein, the universalism of some symbols could come into question. Many cultures ascribe different meanings to symbols. A western reading of a bird in flight, for example, typically centers around freedom. For the Japanese, however, a crane with spread wings symbolizes fidelity.
Some studies have shown that men and women have the same dreams, which raises further questions regarding Freud's conclusion of dreams as wish-fulfillment. After all, it could be argued that men and women have different desires. Furthermore, society places different restrictions on men and women, which in theory, should result in different forms of wish/sexual sublimation between the sexes.
Hobson's dreams as biochemistry
In his book Dreaming, J. Allan Hobson draws heavily on scientific tools used to measure and assess sleep, such as EEGs and recent innovations in brain imaging. Hobson thus found that the brain never completely turns off, even in sleep. The brain's visual and auditory cortexes, for example, remain very active, paving the way for people to have very visual, vivid dreams (Hobson 49).
However, other important parts of the brain are completely shut down, including the centers for self-awareness and logic. For this reason, dreams often involve impossible situations or bizarre and disjointed sequences of events. Since the memory centers are also shut down, people often do not remember their dreams. The best chance to remember a dream is thus to wake up in the middle of it, thereby stimulating the brain's sleeping memory center (Hobson 61-65).
Part of the attraction of Hobson's approach lies in the scientific tools available for inquiry. This does away with the individual and cultural subjectivity that could be ascribed to Freudian interpretation of dreams. It also explains, in biological and biochemical terms, many of the strange things associated with dreaming, such as why dreams are so difficult to remember. It would also explain why mammals, particularly primates, have evolved the capacity to dream.
In Hobson's formulation, dreams did not particularly evolve in humans. Instead, they are merely by-products of the workings - and the sleeping - of the human brain.
In architectural terms, a spandrel is the triangular area between the curve of an arch and the outer rectangular frame. These spandrels are not specifically designed to be parts of the arches; they are merely a result or side-effect of the arches being built.
Flanagan seizes this metaphor to describe dreams as an evolutionary spandrel. For Flanagan, dreams are the spandrels of sleep (Flanagan 105).
Sleep itself has a clear biological function. REM and NREM sleep both have restorative, conservative or constructive functions for the human body. The production of important hormones, such as pituitary hormones and melatonin, thus peak during sleep. REM sleep is associated with the synthesis of neurotransmitters that have been depleted during the day. These complex biological processes evolved so humans can physically survive (Flanagan 71-72).
Dreaming, Flanagan maintains, just came along for the ride.
This position has much in common with Hobson's theories on dreams. Dreams have no real biological function and they are not exaptations of secondary biological functions either. Like Hobson, Flanagan is almost certain that mammals do dream, particularly the ones that have evolved physiologically similar brain structures.
However, while Flanagan does not believe that dreams are grand symbolic expressions of repressed thoughts and desires, neither is he willing to see dreams as mere somatic noise resulting from random neural firings during sleep.
Instead, Flanagan attempts to find a middle ground. Though dreams are not always repressed sexual wishes, they are also self-expressive and have much to contribute towards self-understanding. In fact, he believes that dreams can be self-expressive. They can help in identity constitution, self-knowledge and personal growth (Flanagan 129-131).
The reason for the self-expressive nature of dreams, maintains Flanagan, is largely related to the brain's physiology. During the day, the brain is tasked with processing the bombardment of sensations and experiences, allowing a person to navigate the environment.
This processing continues as a person sleeps. The brain stem works to store thoughts,…