American Scientist

The Interpretation of Dreams. Sigmund Freud. Joyce Crick, trans. Ritchie Robertson, ed. 400 pp. Oxford, 1999. $27.50.

One hundred years ago Freud compared dreams to "a firework that has been hours in the preparation, and then blazes up in a moment," claiming that dreams last for but a brief time and perhaps occur only during awakening and that the thoughts underlying dreams develop slowly during the day. Sleep-lab studies have shown, however, that dreaming takes place longer and far more frequently than he or anyone else could have imagined before the serendipitous discovery of sleep stages in 1953. Freud also asserted that "a reference to the events of the day just past is to be discovered in every dream," but three systematic studies demonstrate that only a little more than half of dreams contain even the slightest "day residue" that can be identified by the dreamer. As part of his emphasis on the large role of memories, Freud believed that all significant speeches in dreams can be traced to memories of speeches heard or sentences read, but the analysis of hundreds of speech acts in dreams collected in sleep laboratories shows they are usually new constructions appropriate to the unfolding dream context, not reproductions.

How many of Freud's other conclusions stand up to empirical findings on dreams generated in the 20th century, particularly in the past 50 years? The 100th anniversary of Freud's The Interpretation of Dreams, being commemorated with Joyce Crick's new translation based on the original text, provides a timely opportunity to explore these issues. Indeed, the new version seems to invite a reassessment because, as the translators acknowledge, the work itself does not change our understanding of any of his ideas. What has changed is our ability to test Freud's ideas about dreams, primarily through studies in sleep laboratories, neuropsychological assessments of brain-injured patients who report loss of dreaming and content analyses of dream reports from people of all ages in all parts of the world, including those who keep dream journals for many years. Many of these studies can be found in David Foulkes's Dreaming: A Cognitive-Psychological Analysis (1985) and Children's Dreaming and the Development of Consciousness (1999); in Mark Solms's The Neuropsychology of Dreaming (1997); and in my Finding Meaning in Dreams (1996).

Freud concluded that "wish-fulfillment is the meaning of each and every dream." He then argued that the simple wishful dreams he collected from young children provide strong evidence for his theory, but Foulkes's five-year longitudinal study in the sleep laboratory of 14 children ages 3 to 8, replicated in a cross-sectional study of 80 children ages 5 to 8, reveals on the basis of hundreds of awakenings that children have static and bland dreams, not at all like Freud's anecdotal examples. Other laboratory studies suggest that the sleep-talking episodes in preschoolers that Freud interpreted as wishful dreams probably occurred during micro-awakenings of a few seconds in duration, of which there are usually several for both children and adults throughout the night.

Freud inferred that a set of cognitive processes unique to sleep called "the dream-work"—condensation, displacement, regard for representability and secondary revision—render many adult dreams incomprehensible at the behest of a censoring agency, thereby making the anxiety-arousing wishes in them acceptable. Two sympathetic reviews of all available experimental studies by Seymour Fisher and Roger Greenberg, The Scientific Credibility of Freud's Theories and Therapy (1977) and Freud Scientifically Appraised (1996), could find no evidence for such processes, which actually seem to be similar to waking figures of speech, if Freud's constant appeal to sexual slang, jokes, etymologies and proverbs in making his interpretations is any indication. Freud further believed that the dreams produced by the dream-work are relatively meaningless unless subjected to interpretation, but dozens of studies summarized by Fisher and Greenberg correlating dream reports and a variety of personality measures suggest dreams provide a considerable amount of information about a person's interests and emotional concerns without the aid of interpretation.

Although Freud anticipated that there would be objections to his wish-fulfillment theory based on anxiety dreams, saying they are dreams in which the censor has failed to disguise the wishes enough to make them acceptable, he did not discuss the repetitive nightmares that are the hallmarks of post-traumatic stress disorder. It was not until the recurrent "war neurosis" dreams suffered by combatants in World War I were brought to his attention that he conceded in Beyond The Pleasure Principle (1920) that "it is impossible to classify as wish fulfillments the dreams we have been discussing which occur in traumatic neurosis, or the dreams during psychoanalysis which bring to memory the psychical trauma of childhood." Although it might be argued that such dreams show a wish to master stimuli, this stretches the theory well beyond what Freud originally had in mind.

Freud thought that people forget most of their dreams at least partly because of repression, a hypothetical cognitive process for which there is little or no convincing experimental evidence. Moreover, investigations of the relation between frequency of recall and various personality and cognitive variables cast doubt on the notion that any process of denial or self-censorship is involved in dream forgetting. So do the results from two different laboratory studies. These investigations demonstrate that the classic memory variables—recentness, length and intensity —best predict which dreams reported after awakenings in the night also are recalled the next morning. In what may be his most sweeping and elegant construction, building on the wish-fulfillment theory and the fact that most dreams are forgotten, Freud theorized that dreams are the "guardians" of sleep, but this idea is contradicted by the low levels of dreaming in young children, the disappearance of dreaming in leukotomized schizophrenics and the loss of dreaming in patients with parietal or bifrontal lesions, all of whom are able to sleep.

Perhaps Freud's most controversial claim was that "impressions from the earliest years of our life can appear in our dreams, which do not seem to be at the disposal of our memory when we are awake," by which he often meant infantile sexual desires from "up to about the end of our third year," as in the case of his interpretation of adults' "nakedness-dreams" as "exhibition-dreams." Such an assertion is highly unlikely in light of modern-day memory research. Like most of Freud's conclusions on the sources of dreams, it rests on free association, his unique method in which the dreamer produces uncritical, unreflective trains of thought to each aspect of the dream. He assumed that these free associations contain the "latent" wishes on which dreams are based, but as Fisher and Greenberg note in their 1977 assessment, "there is not a shred of empirical or reliable evidence that they provide a unique 'true' solution concerning what is contained in the dream."

On the other hand, there is experimental evidence that respect for authority, the subtle suggestions of an experimenter-therapist and cognitive dissonance can be combined to convince many people on the basis of dream interpretations that they were once lost or abandoned as young children. These and other findings on the power of suggestion in a therapeutic context resonate with Freud's several mentions of arguments with patients concerning the wishful and infantile basis of their dreams. What Freud saw as overcoming "resistance" can be seen from the vantage point of social psychology as a process of persuasion and conversion.

Two general ideas remain after sifting through the scientific evidence. First, dreaming is a cognitive process that draws on memory schemas, episodic memories and general knowledge to produce simulations of the real world. Second, dreams have psychological meaning in the sense of coherency, correlations with other psychological variables and correspondences with waking thought. This does not mean they have a "purpose" or adaptive function, which seems unlikely based on current evidence, but their frequent dramatization of emotional preoccupations and their parallels with the metaphoric dimensions of waking thought may be why some societies invent cultural uses for dreams, especially in medicinal practices and religious rituals.

The cognitive nature of dreams is best shown by the gradual development of dreaming between ages 3 and 9. Dreaming is a cognitive achievement related to visual and spatial skills in its frequency of occurrence and to verbal and narrative skills in its length and complexity. Children under age 9 report dreams only 20 to 30 percent of the time from awakenings during REM (rapid eye movement) sleep, which is the most likely—but not the only—stage of sleep to lead to dream reports in adults. The dream reports of children between 3 and 5 consist primarily of static images portraying animals or physiological states like sleeping. Between ages 5 and 8, dreams begin to include physical actions and social interactions on a regular basis. Only around age 8 do children consistently insert themselves as characters who play a role in the dream activities.

As for the psychological meaning in dreams, it is best demonstrated by the relationship between aspects of dream content, most prominently types of characters and social interactions, and such variables as age, gender, culture and individual differences. For example, the percentage of all characters that are animals declines from 40 to 50 percent in young children to 4 to 6 percent in adults in the U.S. and is higher in all preliterate societies where dreams have been collected by cultural anthropologists than it is in industrialized nations. Whatever the culture, men's dreams usually contain a greater percentage of physical aggressions than do those of women, but there are also large differences from culture to culture in the occurrence of physical aggression in men's dreams.

Cross-sectional data from several different investigations reveals that dream content varies little or not at all in any of several categories from young adulthood to old age, except for a possible decline in aggressive interactions and negative emotions, and longitudinal studies of lengthy dream journals demonstrate great consistency in what individuals dream about over years and decades. Inferences about a person's interests and concerns based on blind analyses of 100 or more dream reports demonstrate that there is considerable continuity between dream content and waking emotional concerns. The content analysis of many dreams from a single individual is especially accurate in portraying waking personal relationships.

The psychological view of dreams first championed by Freud has been the object of an all-out critique over the past 25 years by Harvard psychiatrist J. Allan Hobson, author of The Dreaming Brain (1988), who claims that almost all dreams are delusional, psychotic-like cortical reactions to the periodic random firings and neurochemical changes in the brainstem that trigger REM sleep. Many people seem to think that his theory is the ultimate refutation of Freud's basic ideas, but Hobson's equation of dreaming and REM sleep is called into question by the presence of many more full-blown dreams during non-REM sleep than he concedes, especially late in the sleep period; by the occurrence of REM sleep without dreaming in young children, leukotomized schizophrenics and patients with parietal and bifrontal lesions; by the lack of any correlation between specific neurological events in REM sleep and dream content; by the realistic and coherent nature of most dream content; and by the consistency of dream content in at least some individuals over many decades. More generally, his theory tries to reduce the psychological to the physiological in a way that may never be possible.

As the 21st century begins, the hope for a new psychological theory of dreams that would fulfill Freud's ambitious agenda rests on a possible synthesis of findings from developmental cognitive psychology, neuropsychology and content analysis. This potential synthesis would have little or nothing in common with Freud's specific claims, nor with those of Jung or the neo-Freudians, for that matter. Meanwhile, the distance between those who believe there is a mind in sleep and those who would reduce dreams to epiphenomenal shadows on the cranial walls remains as vast as it was when Freud first set pen to paper. Let us hope that the new century sees more incorporation than did the past one of dreams into the cognitive sciences.