© 2009 admin

research on evolution and dreams

Threat Simulation Theory
Originally proposed by Finnish neuroscientist Antti Revonsuo, this clever evolutionary theory holds that dreaming serves a biologically adaptive function because it allowed our ancestors to simulate problem-solving strategies for genuine, waking life threats. Antonio Zadra, Sophie Desjardins, and Eric Marcotte of the University of Montreal neatly summarize the central argument of the theory this way: “By giving rise to a full-scale hallucinatory world of subjective experience during sleep, the dream production mechanism provides an ideal and safe environment for such sustained practice by selecting threatening waking events and simulating them repeatedly in various combinations.” What we should see in contemporary dreams, argues Revonsuo, are “threat scripts” depicting primitive themes of danger that would likely have been relevant in the ancestral environment, such as being chased, falling and so on.

Dreaming as Problem-Solving

Barrett’s preferred evolutionary explanation for dreaming, and the one she’s best known for, is that dreamscapes provided our ancestors (and therefore us) with a sort of creative canvas for solving real-world problems. In support of this, Barrett describes the work of Stanford University psychologist William Dement, who in the early 1970s instructed hundreds of undergraduate students to work on a set of challenging brainteasers before bedtime, so that they’d fall asleep with the problems still on their mind. For example, “The letters O, T, T, F, F … form the beginnings of an infinite sequence. Find a simple rule for determining any or all successive letters.” [The correct sequence is the first letter of each number, so the next one would be “S” for “six.”] One participant who went to bed frustrated by this brainteaser dreamed:

I was walking down the hall of an art gallery. I began to count the paintings—one, two, three, four, five. But as I came to the sixth and seventh, the paintings had been ripped from their frames! I stared at the empty frames with a peculiar feeling that some mystery was about to be solved. Suddenly I realized that the sixth and seventh spaces were the solution to the problem.

Barrett also cites many examples of notable figures from all walks of life (including scientists) who similarly arrived at their groundbreaking discoveries and insights through dreams. These include the German chemist August Kekulé’s famous dream of a snake grabbing its own tail leading to his discovery of the benzene molecule structure, and Demitri Mendeleev’s literal dream of the periodic table for classifying chemical elements. Such anecdotes, as well as an impressive range of experimental findings, suggest to Barrett that a simple brain conditioning explanation for the existence of dreaming is shortsighted. In some conditions, she notes, “sleeping on it” may be better than waking thought.”

From “Dreaming of Nonsense: The Evolutionary Enigma of Dream Content” by Jesse Bering

Comments are closed.