You may have been warned to never wake a sleepwalker. It is good advice but not for the reason you might think.
Sleepwalking, also known as somnambulism, is a condition which sees people arise in a state of minimal consciousness and carry out activities that they are familiar with when awake. They can do many things, from raiding the fridge for a midnight snack to something as horrifying as murder. The average time of sleepwalking is 30 minutes but has been reported to last most of the night for extreme sufferers.
We’ve been told not to disturb a sleepwalker because it could cause them serious injury or even death. We seem to accept this as fact but how true is the claim? In order to evaluate this we need to look back to when sleepwalking was popularised as being dangerous. Walter Cooper Dendy, a London surgeon, recalled the case of a young woman who in 1841 was abruptly awakened by a relative and “almost instantly died.” This caught the public’s attention and created an entire falsity around somnambulism. However, there is no validity to Dendy’s second hand report because we have no verified case of spontaneous sleepwalker death throughout all medical writings. Therefore, scientists have no evidence to corroborate the claim that sleepwalkers are directly injured from being awoken during their automatism.
It is far more likely for the ‘waker’ to be harmed. When the sleepwalker is abruptly pulled out of their trance-like actions, they will be disorientated, confused and distressed by their situation. Consider the feeling you get once you wake up from a deep sleep. Amplify this by imagining coming to consciousness in an environment other than where you drifted off- it’s pretty daunting. In their confusion, they can lash out at the person who just shook them awake. To avoid this surprise for both parties, researchers who study sleepwalking recommend that (if possible) gently guide the person back to bed without waking them.
While the waking of a sleepwalker cannot cause harm, the wanderers can still bring themselves into danger through their nocturnal liveliness. For instance, in 2007 a teenager in Germany strolled straight out of a five-storey apartment window and broke an arm and leg while still managing to get a full night’s rest before he was discovered in the morning.
A substantial number of sleepwalking cases are reported in children. In fact, an estimated 25% of adolescents have experienced at least one episode between the ages of 4 and 8. This diminishes with age as proven by a study showing that only 3.7% of adult participants reported more than two sleepwalking events in a month.
While the age-old tip to not wake a sleepwalker is somewhat true, the actual rationality behind such advice is worth heeding if you want to avoid a broken nose.
Psychology (2nd ed.) 2011; Section 5.7