Whether or not precognitive dreams are real, or have similarities to future events, is a subject of debate amongst scientists and cognitive psychologists. As explained in HowStuffWorks, researchers have linked precognitive dreams to déjà vu feelings that their subjects later reported, experiences that occurred during a time frame of one day to eight years after the dream.
As explained in Psychology Today, despite research in physics that has theorized the nature of time and retrocausality, the common belief in psychology is often understood in terms of mechanical materialist dogmas. One of these dogmas holds that the future cannot influence the present or past events. However, studies in retrocausality show that an effect can occur before its cause.
New psychological research is examining time deviations concerning precognition in dreams. However, researchers have not determined why the phenomenon of déjà vu occurs, and what it signifies. Déjà vu is French for "already seen." It is an experience in which someone has a strong feeling that an event has already occurred, even if there is no evidence that the event actually took place.
According to surveys, approximately 50 percent of the general population has experienced a recent precognitive dream that they report gave them knowledge about the future which they could not have known through any other means.