The dreams-for-survival theory states that dreams have helped humans evolutionarily by simulating threats, thus preparing people to fight for survival. It is also called the threat simulation theory.
The theory stems from the notion that many dreams are stressful. When humans are dreaming, they are often dreaming of situations in which they need to fight to survive. This essentially provides practice for survival instincts and functions as a defense mechanism.
A study conducted in Finland in 2005 advanced the dreaming-for-survival theory by analyzing the dreams of children who had experienced many traumatic events and children who had not. The researchers predicted that the experience of the Kurdish children, who had been subject to war and constant danger, would have honed their survival instincts and therefore, they would have higher instances of stressful dreams. The findings supported this prediction, as the Kurdish children reported more intense and more frequent threatening dream events than the group of Finnish children, who had led relatively normal childhoods.
Dreams have been a mystery and a subject of studies and theories in many disciplines, including psychology, evolutionary anthropology and neuroscience. The renowned psychoanalyst Sigmund Freud was particularly interested in them as a manifestation of the unconscious mind. He emphasized the need to separate the actual content of the dream from the overall theme or feeling, which tended to symbolize other events in the dreamer's life.