The Promised Neverland- Childhood Amnesia
The Promised Neverland is a new Shonen Jump series written by Shirai Kaiu and drawn by Demizu Posuka. It was first released in August, 2016, and 29 chapters have been translated into English. You can find the most recent chapters here http://mangastream.com. It is an ontological mystery and survival game with a bit of horror thrown in for good measure. The Promised Neverland is one of my current favorites and I highly recommend it, but the reason I am discussing it today is for its use of the concept of childhood amnesia or the lack thereof to give one of the main characters an advantage in their current situation. I will be keeping this post as spoiler free as possible, so feel free to read on even if you haven’t read The Promised Neverland yet.
Infantile or childhood amnesia was first described and recorded all the way back in 1893 by Caroline Miles. Childhood amnesia is the phenomenon where adults are unable to recall memories from before they were 3 to 4 years old. This does not mean it is impossible to remember events from before the age of 3, just that these memories would be few and far between and the ability to remember would vary wildly between individuals. Up until around the 1980s it was thought that the immature state of a young child’s brain prevented them from forming permanent long term memories. However, this turned out to not be the case as Patricia Bauer and other researchers began to study memory in young children.
As it turns out, a study was done proving that young children can actually form long term memories and 60% of the children under the age of seven that were tested could remember events from before the 3 to 4-year-old cutoff. By age nine, only 40% of the children tested could remember events from before the 3 to 4 year-old cutoff. So it is around this time that childhood amnesia really begins to set in. The current thinking about this dramatic drop in memory recall from age 7 to 9 is that it is due to immaturity of the child’s brain. The neurological pathways that form memories are functional, but are not fully formed, and this means that the ability of a child’s brain to store memories is less effective than an adult brain.
How is it then that some people have memories from an early age? The memories from before the age of 3 to 4 are linked to extreme emotions. The extreme emotions experienced during the event enhance the brain’s ability to form connections and memories. This matches with how many of the events that people remember from an early age are often significant and emotional events that had an impact on their life. Women tend to do a bit better at recalling earlier memories, which is linked to how women do slightly better than men at recalling all early events, and men tend to remember negative events more often on average. There are cultural differences as well with Chinese and Koreans having later first memories, and this is thought to be linked to the collectivist culture of those countries.
This of course brings us to the crux of the matter, how is it that one of our main characters remembers events from the moment of his birth? Eidetic and photographic memory, while they are often used to signify a person who can remember everything, they are in fact two different forms of memory. Eidetic memory is the ability to recall a vivid after image of an event, which includes visual, auditory, and other sensory information. Photographic memory, on the other hand, refers to being able to remember large blocks of text, and/or numbers with a single look, without the after images that are seen in eidetic memory. The jury is still out on the validity of either type of memory, but there is some evidence to support eidetic memory, while there is no valid evidence of an individual having photographic memory. Several studies have found evidence of eidetic memory in 2-10% of children, and they tend to grow out of it by age ten. These children also have the same issue of childhood amnesia as the general population, so they won’t be remembering every single detail of their early years either.
So where does that leave our intrepid main character? Let’s assume, given the circumstances present in The Promised Neverland, that our main character is one of those 2-10% who has an eidetic memory, and he had some emotional experiences during his early years. Then it is entirely possible that he could have some memory of events prior to the group’s current location. The only caveat to this is that he would have had to have written down a record of said events to get around the childhood amnesia effect, given the age the characters are at the start of the manga. This is also not including the lack of context he would have to fully understand some of the memories, context that would not come until much later. So, in the end I would say the situation is a rather exaggerated plausible, that really stretches the limit of science, but one that does not blow my suspension of disbelief for the story.