New research concludes that dreams may not mean anything but they shape humans'judgment and behavior.
The findings are based on six different studies, in which researchers surveyed nearly 1,100 people about their dreams.
"Psychologists' interpretations of the meaning of dreams vary widely. But our research shows that people believe their dreams provide meaningful insight into themselves and their world, "said Carey Morewedge, an assistant professor at Carnegie Mellon University and the study's lead author.
In one study that surveyed general beliefs about dreams, Morewedge and colleagues surveyed 149 university students in the United States, India and South Korea.
The researchers asked the students to rate different theories about dreams. Across all three cultures, an overwhelming majority of the students endorsed the theory that dreams reveal hidden truths about themselves and the world.
In another study, the researchers wanted to explore how dreams might influence people's waking behaviour.
They surveyed 182 commuters at a Boston train station, asking them to imagine that one of four possible scenarios had happened the night before a scheduled airline trip: The national threat level was raised to orange, indicating a high risk of terrorist attack; they consciously thought about their plane crashing; they dreamed about a plane crash; or a real plane crash occurred on the route they planned to take.
A dream of a plane crash was more likely to affect travel plans than either thinking about a crash or a government warning, and the dream of a plane crash produced a similar level of anxiety as did an actual crash.
Finally, the researchers wanted to find out whether people perceive all dreams as equally meaningful, or whether their interpretations were influenced by their waking beliefs and desires.
In another study, 270 men and women from across the United States took a short online survey in which they were asked to remember a dream they had had about a person they knew.
People gave more importance to pleasant dreams about a person they liked as compared to a person they did not like, while they were more likely to consider an unpleasant dream more meaningful if it was about a person they disliked.
"In other words, people attribute meaning to dreams when it corresponds with their pre-existing beliefs and desires," said Morewedge.
The article appears in the February issue of the Journal of Personality and Social Psychology.