Answer: Somnambulism

Sleepwalking, frequently thought of as the province of fiction (with perhaps the most famous example found in Act V of Shakespeare’s Macbeth) is a surprisingly common occurrence.

Sleepwalkers, or in medical terms, those suffering from somnambulism (derived from the Latin words “somnus” for “sleep” and “ambulo” for “to walk”), experience a state of mixed wakefulness and sleep that occurs during slow wave sleep and leads the patient to rise from their bed, move about, and even sometimes perform hazardous tasks like driving or cooking. Nearly one-third of people experiencing somnambulism have a family history of the disorder and approximately 3.6 percent of U.S. adults are prone to the condition and have experienced it within the past year.

While the disorder is poorly understood, there is a strong indicator that sleepwalking is a genetic trait with the incidence of sleepwalking in children rising based on whether one or both parents had experienced the condition in the past. If both parents are sleepwalkers, there is a 60 percent chance that their children will also experience the disorder at some point.