I have never been an only child. Born in the middle, I have always had to share the attention of my parents. A brother soon followed who was born when I was 17 months old, so I don't remember a time before he bulldozed into my existence. My son, however, was over three years old by the time I had my daughter, and I sometimes wonder if he remembers life before her, as he often references it. I am curious if this is the age when toddlers can remember life before their sibling was born.
The field of memory science seems to be an ever-evolving arena of research. David E. Pillemer wrote in Momentous Events, Vivid Memories, that there are certain memory markers that tend to brand themselves into the brain, allowing all of us to recall the time and space surrounding that momentous event. The birth of a sibling would definitely fall into the category of a "momentous event," and would therefore have the ability to be remembered long into the future. However, the question remains: Would the seemingly mundane, quotidian activities of life before bringing a baby home be enough to spur a level of recall in a toddler?
For a few years after my daughter was born, my son would remember bits and pieces of his life before she came into the picture. He would talk about his speech therapists coming to our house, or going to see his aunt's giant dog. It was mostly little things that seemed to have been sticky in his brain, but he could recall them vividly. Now, at age 11, he no longer recalls his long days in therapy as a toddler, or the giant akita that passed just before his fourth birthday, in spite of the fact that they were thick as thieves when he was a little guy.
Where does that memory end? At which point can science confidently declare that this is the age when toddlers can remember life before that next baby came along? I contacted Dr. Dana Dorfman, PhD, psychotherapist and co-host of the podcast Two Moms On The Couch, and asked her about the place in which toddlers have some level of memory permanence in regards to their life before becoming a big sister or brother. She tells Romper that this is a tricky thing to determine, even for psychologists, because, "Childhood memory is complicated and our understanding of memory continues to evolve."
Dr. Dorfman says that "Memory researchers report that small children can retain memories from around 20 months, though they typically fade between the ages of 4 and 7 years old." That tracks with my son, who really started losing those early memories in the past few years; now, they're all but gone. She continues, saying, "Infants and toddlers do have memory systems, but many factors influence whether they are stored in long term memory." Dorfman notes that one of these factors is "the emotional significance of the event," such as the birth of a sibling. Also, as memory is developing, so is their grasp of language, and their ability to manipulate that language into coherent conversations surrounding an event.
Dorfman suggests that because of this co-development, "an older sibling of 3 years old, may recall memories of or surrounding the event (images, feelings, smells), but may not be able to verbally recall experiences prior to the birth of the sibling in adulthood." At some point those memories that are formed get blurry around the edges. A smell might be recalled, a sense of an occasion, but not necessarily what the specifics were at the time of the birth of a child, or the time before they were born.
One thing is for certain: With all the pics and videos you've taken of your toddler since birth, he'll never have to wonder what his first years were all about (whether he can "remember" or not).