Studies conducted in 1993 and 2009 indicated that people do not always dream in color. According to both studies, about 80 percent of people who are younger than 30 dream in color. The results of both surveys demonstrated that as the age of the participants increased, the percentage who dream in color decreased. Participants who were older than 60 were much more likely to dream in black and white, with about 20 percent of people in that age group reporting dreams in color.
Facts about dreams:
- It was once believed that dreams occur only during rapid eye movement (REM) sleep, but many scientists now believe that dreams can occur during any phase of sleep. Dreams that occur during REM sleep can often be somewhat unusual, and dreams that occur during other sleep states tend to be more normal.
- Theories differ about why humans dream. One school of thought holds that people dream as a way to lock in things that are considered worth remembering. An opposing point of view holds that dreaming is a strategy that helps to eliminate memories that are not worth holding onto.
- Species other than humans also are believed to be capable of dreaming. Elephants, for example, are believed to be able to dream while standing up during non-REM sleep. When a dream occurs during REM sleep, the elephant will lie down.