Why the heck do we dream anyway? There's an gigantic body of lit on this topic Wake deterioration and sleep restoration of human learning. Mander, B.A., Santhanam, S., Saletin, J.M. Current Biology. 2011 Mar 8;21(5):R183-4. Memory, Sleep and Dreaming: Experiencing Consolidation. Wamsley, E.J., Stickgold, R. Harvard Medical School/Beth Israel Deaconness Medical Center, Boston, M.A. Sleep Medicine Clinics, 2011 Mar 1;6(1):97-108. Another look at dreaming: disentangling Freud's primary and secondary process theories. Robbins, M. Boston Psychoanalytic Society, USA. Journal of the American Psychoanalytical Association, 2004 Spring;52(2):355-84.. But Calvin Kai-Ching Yu, author of a new study on why some of us have sexier sleep cycles than others, thinks our dreams have more to do with the positions we sleep in than any unconscious impulses Freud and co. suggested.
Yu recruited 670 undergrads enrolled in a Hong Kong University to fill out a Big Five personality inventory. Each student was evaluated on how neurotic, extraverted, open to experience, and agreeable they were — as well as how defensive they became in various social situations. Yu then logged the themes — losing teeth, having to pee, being trapped, falling, flying, or doing something naughty — that ran through students’ minds. He then tallied how often students said they slept on their backs, stomachs, or sides.
Four hundred and seventy six of these dreamers said they had only one preferred sleeping position. Just 5 percent said their one and only sweet sleep spot was face down. This thin slice of face-down sleepers also reported dreaming more vividly, intensely, and erotically than one-side-only or multiple position-preferring sleepers. Previous research into the way we sleep found that peeps with a preference to snooze on their right sides have fewer nightmares than left-leaning sleepers. Other than that, people who smush their faces into a pillow during resting hours don’t tend to wake up so happy.
Yu thinks the physical sensations felt by our nether regions whilst sleeping on our bellies explains the more stimulating overnight experience belly-sleepers report. Basically, the way a person sleeps triggers certain somatic or sensory excitations, Yu wrote in a paper he published in the journal “Dreaming.” Sleeping on one's genitals, for example, will theoretically help construct a sexier dream because that area receives stimulus by the sleeping position.
Can We Trust It?
Yu acknowledges self-reports of sleep positions should be taken with a grain of salt — none of the students were filmed as they slept, so their nocturnal positions may be a bit different from what they assume. But across the board, personality traits and degree of defensiveness in social situations didn't have a significant effect on dream content or intensity of sexiness during sleep. Whether participants recalled sleeping on their tummies was the strongest predictor of whether they also recalled dreaming on the dirty side.
No matter how extroverted, introverted, neurotic, or rigid we may be, passing out prone could be our secret to more, um, “stimulating” sleep cycles.
How has your sleep been affected by sleep position? Let us know in the comments below or tweet Katherine at @KTschreib.