Dreaming is a cognitive achievement that develops gradually over the first 8 or 9 years of life.

The association cortices, paralimbic structures, and limbic structures may operate as a closed loop to generate the process of dreaming. This loop is the starting point for the neurocognitive model proposed in this book. On the one hand, this subsystem is cut off from the primary sensory cortices that provide information about the external world and, on the other, from the prefrontal cortices that integrate incoming sensory information with memory and emotion in the process of decision making (cf. Braun et al., 1998, p. 94). This model implies that an unconstrained and freewheeling conceptual system can operate when sufficient activation occurs. (..) On the basis of current evidence, it is more likely that dreams are an accidental by-product of two great evolutionary adaptations, sleep and consciousness - many structures and processes persist even though they have no function; dreaming may be one of them (Flanagan, 1995, 2000a).

Dreaming cannot be triggered by external stimuli and it is difficult to influence dream content with either presleep stimuli, such as fear-arousing or exciting movies, or with concurrent stimuli administered during REM, such as a spray of water, sounds, or the names of significant people in the dreamers’ lives (Foulkes, 1985, 1996a; Rechtschaffen, 1978).


Everywhere in the world, for example, women and men have the same differences in the percentage of gendered characters who are men or women. Women dream equally of men and women, but 67% of the gendered characters in men’s dreams are other men (Hall, 1984). (..) For both men and women cross-culturally, dreams usually contain more aggression than friendliness, more misfortune than good fortune, and more negative emotions than positive emotions. In addition to these similarities, there are also a few differences that make sense on the basis of cultural differences. For instance, people in small, traditional societies have a higher percentage of animal characters in their dreams than people from large, industrial societies. Moreover, there are large variations from society to society in the percentage of all aggressive interactions that are physical in nature, although men in most societies have a higher percentage of physical aggression in their dreams than women do (Domhoff, 1996; Gregor, 1981; O’Nell & O’Nell, 1977).

The studies attmpted to find personality differences between those who recall dreams and those who do not (..). The most important finding from the studies, which used a wide range of personality tests, is that no consistent differences exist between recallers and nonrecallers (Domhoff, 1996, chapter 3).

//G. William Domhoff, 2002, The Scientific Study of Dreams