Childhood amnesia is the inability of adults to retrieve episodic memories (memories of situations or events) before the age of 2 to 4 years. It may also refer to the scarcity or fragmentation of memories recollected from early childhood, particularly occurring between age 2 and 6.
Childhood amnesia is a normal part of brain development. Episodic memories involve the hippocampus, a part of the brain found in the temporal lobe, which is not fully developed at birth. The hippocampus should be ready at about the age of 4.
Memories that are not repeatedly re-told and strengthened become lost over time. For a long time, scientists thought childhood amnesia occurred because the brains of young children simply couldn't form lasting memories of specific events.
More studies provided evidence that at some point in childhood, people lose access to their early memories. And they found that children as old as 7 could still recall more than 60 percent of those early events, while children who were 8 or 9 recalled less than 40 percent.
On average, this fragmented period wanes off at around 4.7 years. Around 5-6 years of age in particular is thought to be when autobiographical memory seems to stabilize and be on par with adults.
Furthermore, a small child’s identity is not centered around the importance of memory—it’s not something they’ve been taught to focus on yet, says Robert Kraft, PhD, professor of cognitive psychology at Otterbein University.
Young children aren’t that interested in memory; they mostly just live in the moment, he says. But then eventually, they learn that remembering experiences is a skill to master.
“When parents start reminiscing about past vacations or when they start asking questions about what happened at a friend’s house, toddlers learn that remembering is something adults do and something that should be practiced and learned,” Dr. Kraft says.