Most adults struggle to recall events from their first few years of life and now scientists have identified exactly when these childhood memories fade and are lost forever.
A new study into childhood amnesia – the phenomenon where early memories are forgotten – has found that it tends to take affect around the age of seven.
The researchers found that while most three year olds can recall a lot of what happened to them over a year earlier, these memories can persist while they are five and six, but by the time they are over seven these memories decline rapidly.
Most children by the age of eight or nine can only recall 35% of their experiences from under the age of three, according to the new findings.
The psychologists behind the research say this is because at around this age the way we form memories begins to change.
They say that before the age of seven children tend to have an immature form of recall where they do not have a sense of time or place in their memories.
In older children, however, the early events they can recall tend to be more adult like in their content and the way they are formed.
Children also have a far faster rate of forgetting than adults and so the turnover of memories tends to be higher, meaning early memories are less likely to survive.
The findings also help to explain why children can often have vivid memories of events but then have forgotten them just a couple of years later.
Professor Patricia Bauer, a psychologist and associate dean for research at Emory college of Arts and Science who led the study, said: “The paradox of children’s memory competence and adults’ seeming “incompetence” at remembering early childhood events is striking.
“Though forgetting is more rapid in the early childhood years, eventually it slows to adult levels.
“Thus memories that “survived” early childhood have some likelihood of being remembered later in life.”
Professor Bauer and her colleagues studied 83 children over several years for the research, which is published in the scientific journal Memory.
The youngsters first visited the laboratory at the age of three years old and discussed six unique events from their past, such as family outings, camping holidays, trips to the zoo, first day of school and birthdays.
The children then returned for a second session at the ages between five years old and nine years old to discuss the same events and were asked to recall details they had previously remembered.
The researchers found that between the ages of five and seven, the amount of the memories the children could recall remained between 63-72 per cent.
However, the amount of information the children who were 8 and nine years old dropped dramatically to 35 and 36 per cent.
When the researchers looked closely at the kind of details the children were and were not able to remember, they found marked age differences.
The memories of the younger children tended to lack autobiographical narrative such as place and time. Their memories also had less narrative, which the researchers believe may lead to a process known as “retrieval induced forgetting” – where the action of remembering causes other information to be forgotten.
As they children got older, however, the memories they recalled from early childhood tended to have these features.
Professor Bauer said: “The fact that the younger children had less-complete narratives relative to the older children, likely has consequences for the continued accessibility of early memories beyond the first decade of life.
“We may anticipate that memories that survive into the ninth or tenth year of life, when narrative skills are more developed, would continue to be accessible over time.”