Many people enjoy reminiscing about their childhood, but when it comes to recalling early memories, especially those from the first five years of life, their memory often falters. Why does this happen? The answer lies in a phenomenon known as infantile amnesia.
What Is Infantile Amnesia?
The concept of infantile amnesia was first described by Sigmund Freud in 1905. He defined it as a phenomenon covering the first five years of life, during which memories are stored only fragmentarily or are entirely absent. Freud suggested that this amnesia serves as a protective mechanism, shielding the child’s consciousness from the trauma associated with vivid impressions, the discovery of their own body, and the surrounding world. At early stages of development, the child’s brain is not capable of processing and storing such data correctly due to a lack of necessary knowledge and experience.
Age of Onset
Scientists continue to study infantile amnesia and its manifestations. One experiment involved interviewing 3-year-old children about their memories. When the same children were interviewed at ages 5-7, they could only recall 60% of their earlier memories. By ages 8-10, this percentage dropped to 40%. This led researchers to conclude that infantile amnesia typically sets in around age 7.
Interestingly, geographical location may influence how long early memories last. Studies have shown that 5-year-old children in Canada could recall about 60% of their early memories, whereas their peers in China could only remember 30%. This difference may be due to cultural factors that emphasize personal versus family events.
Problems with Memory Encoding
Another reason for infantile amnesia is children’s inability to associate events with specific places, times, or details. At an early age, spatial and temporal criteria are not effectively recorded in memory, making recollections fragmented. For instance, a child might remember being at a circus but not recall when it happened or with whom they were.
There is also a hypothesis that early memories are not retained due to a child’s limited vocabulary. The brain lacks the linguistic skills needed to encode these memories, so they may become blocked and not stored.
Neurogenesis and Memory Erasure
Canadian scientist Paul Frankland proposed another intriguing theory. He argues that children’s memories are erased due to the process of neurogenesis — the formation of new neurons in the brain. This process is most intense before the age of 5. While new neurons help in forming new memories, they can also cause old ones to be erased. After age 5, neurogenesis slows down, allowing memories to be stored more stably.
Frankland conducted experiments on mice to support his theory. He found that young mice, which passed through an electric shock cage, quickly forgot their negative experience and entered the cage again without fear the next day. Older mice, with less active neurogenesis, remembered the danger and avoided the cage.
Conclusion
Infantile amnesia is a natural phenomenon linked to brain development and the specifics of memory formation at an early age. Although it can be frustrating for those who wish to remember their early childhood, scientific research shows that this process has logical explanations and is a part of normal human memory development.