When asked “what are your dreams?”, the colloquial understanding for the word “dreams” is often synonymous with “wishes” or “aspirations,” perhaps even inferring those desires which one hopes would come true but does not expect to ever manifest. This is in effect how we think of dreams in the light of day, but it has been supposed that night dreams, too, reflect our waking wants. This could be a vestige of Freud’s conception of the meaning of dreams, a wish-fulfilling chimera presented behind closed eyelids. In contrast to this cheery conception of our somnial experiences, the scenarios perceived during night repose are, more often than not, quite dark.
Researchers in the field of dream studies are far from being in agreement as to what function, if any, dreaming satisfies (Valli, Lenasdotter, MacGregor, & Revonsuo, 2007). Dreaming has been proposed to serve various ends, from protecting the sleeper from becoming aware of their true longings (Freud, 1900/1961) to supplying the mind with creative solutions to waking problems (Cartwright, 1974), from contextualizing and weaving emotional concerns into one’s personal history (Hartmann, 2010) to nothing at all, a mere epiphenomenon of REM-Sleep (Hobson & McCarley, 1977). A recent proposal for the function of dreaming, and the focus of the current study, follows an evolutionary-psychology perspective and synthesizes a broad range of evidence into the conclusion that the dream system is an ancient adaptation which supports survival by allowing humans to practice detecting and handling threatening situations in a safe, virtual environment (Revonsuo, 2000).
An inherent challenge in dream research is that dreams are only directly observed from the first-person, dreamer oriented perspective, and must be reported post facto. Be that as it may, it is still possible to learn what is typical of dream content by collecting dream reports from large samples of populations and quantifying this information through the use of coding systems. Dream coding systems allow for the quantification of what would otherwise be a mere collection of stories. Once dream content has been assigned numerical short-hand and multiple dreams are compared either between or within individual collections, characters, settings, emotions, behaviors, and even themes can be assessed.
Approaches to teasing out the “meaning” or functions of dreaming which do not give typical dream content a central role in theory formation have found the null hypothesis to dominate in research results, if and when the theories are even empirically based. A seminal theorist in dream studies, Freud saw in dreams the achievement of unconscious wishes hidden within symbolic imagery (1900/1961). A major issue with this Freudian conception is that dreams containing obvious desire-gratifications are in line with the dream-as-wish perspective, and those night sojourns which deviate from this format, such as in frightening scenarios, are said to be wishes in disguise. The Freudian perspective does not welcome empirical verification nor refute.
Another popular idea is that dreams support waking-problem solving, and this can and has been tested. Cartwright (1974) hypothesized that participants’ performance would improve on crossword puzzles, Remote Associations Tests, and Thematic Apperception Test (TAT) story completions following a period of sleep in comparison to an equal span of waking. Performance on the puzzles and associations did not significantly change following sleep; what did change were the TAT completions. Story endings bent toward more unsuccessful resolutions after sleeping. Results such as Cartwright’s hinted that sleeping, if not dreaming, may serve some cognitive function counter to what popular opinion suspected.
The Continuity Hypothesis states that waking experiences and concerns are reflected in dreams (Schredl & Hofmann, 2003). Although so-called “day residue” does often appear in dreams, predicting which day events will enter into dreams is notoriously difficult, and those that do are isolated fragments of episodic memories, rarely long replays of waking life (Nielsen & Stenstrom, 2005). Although the Continuity Hypothesis decrees no explicit function to dreaming, it is worth noting that traumatic experiences may be followed by highly episodic nightmares.
Hartmann (2010) is a leading proponent for what is known as the Contemporary Theory of Dreaming. Hartmann believes that dreams contextualize the dreamer’s predominant waking emotion as a “Central Image.” often guided by waking experiences which are traumatic or stressful. By use of a hyper-connectivity between normally disparate memory traces, dreaming might encourage emotional inter-weaving of disturbing affections. Support for the Contemporary Theory is presented as case-study examples, and Central Images of dreams are said to represent waking concerns, but rarely depict these concerns veridcally. For instance, feeling overwhelmed may be contextualized as a tidal wave chasing and overtaking the dreamer. The Contemporary Theory cannot account for recurring dreams, especially those which continue throughout one’s lifespan, which do not weave-in to a more peaceful conclusion, and nightmares and post traumatic disorder dreams must be viewed within the Contemporary Theory framework as a failure of the dream system.
Dreaming has also been described as an epiphenomenon of REM-Sleep, with no useful function in its own right. This shadow-like attribution of dreaming was championed by Hobson (1977) in his Activation-Synthesis model wherein dreams were derogated to the sleeping brain’s attempt to make sense of meaningless memory activations triggered by excitatory waves sent up to the cerebral cortex from the brain-stem. Hobson has compared dreams to the cogitations of psychosis. The Activation-Synthesis model cannot account for why so many dream reports across cultures, time, and individuals display very typical content, nor why dreams appear to be rather coherent and story-like.
Rather than starting with a theory of dream function and testing this with hypotheses, dream reports can be content analyzed and compared in order to obtain a picture of what is common across dreams. Taking a similar and less time-costing approach, lists of dream themes can be presented to participants and themes can be selected for their frequency of occurring, for which theme occurred earliest in participants’ lives, for most often occurrence, etc. By content analyzing dream report content and by collating typical dream themes, trends in these data can be used to form meaningful hypotheses, or otherwise give a picture as to what elements typical dreams are composed.
Hall and Van de Castle (1966) created a content analysis system which contains categories for dream report content, including “Misfortunes/Fortunes,” “Aggression/Friendliness,” “Characters,” etc. In their normative study of 500 male and 500 female American University students, Hall and Van de Castle found that dream reports were clearly slanted toward depicting negative content: there were seven times more misfortune than good fortune, there was a ratio of 59% in men’s and 51% in women’s dreams of aggressive compared to friendly interactions. Under the subclasses of aggression, being attacked or chased made up 37% of aggression in male participants’ dreams, while 36% of females’ dream aggressions are from “Rejection.” Many studies have replicated the original Hall and Van de Castle normative study and similar content frequencies have been found time and time again (Domhoff, 2008). As Domhoff points out, the Hall and Van de Castle normative study did not explicitly infer a reason or function for the negative content so typical of dreams. The Hall and Van de Castle normative data are also somewhat myopic, in that they focus on detailed content of dreams and do not portray thematic typicality.