Why dream amnesia may be adaptive: dream recall frequency predicts dream-reality confusion

Abstract

Dreaming is a universal phenomenon, yet the ability to recall dream content varies among individuals and most dreams are forgotten quickly after waking up. Such dream amnesia seems paradoxical given the proposed adaptive functions of dreaming. It has been theorized that dream amnesia might serve an evolutionary adaptive function, protecting against cognitive disruptions such as dream-reality confusion. The present study tested this hypothesis by examining the association between dream recall frequency and dream-reality confusion. By analysing data from 4,961 adults participating in a population-based survey, we show that more frequent dream recall is associated with a higher likelihood of dream-reality confusion. The association held after controlling for age, sex, and lucid dreaming frequency. Moreover, individuals with higher dream recall frequency were also more likely to report dream-reality confusion experiences as more personally relevant and disruptive to daily functioning. We propose that while dreaming may support implicit learning processes (e.g., social or threat simulation), limiting explicit recall of dream content may help maintain a clear distinction between internally generated and externally experienced events. These findings contribute to a broader understanding of the functional role of memory processes in dreaming. However, longitudinal and experimental studies are needed to determine whether dream amnesia plays a protective causal role.