Why Don't Toddlers Remember a Damn Thing? Asks Science

Researchers now have a hypothesis for the reason your 4-year-old niece insists on telling you the same story over and over every time she sees you. Alas, there are no new findings on how not to look bored.

The quick development of nerve cells in the hippocampus — the part of the brain that tucks our new memories away into the long-term file — may be what causes what researchers refer to as “infantile amnesia,” the reason you probably can’t remember anything from age 3 or younger.

Paul Frankland, a senior scientist at the Hospital for Sick Children in Toronto and co-author of the study, theorizes that the memories are actually in there somewhere, but not stored in the proper order, thanks to the overload of brain development and activity during those first three years.

He tested out his theory on baby mice, teaching them how to navigate a maze and then slowing down the hippocampus growth in half of them, which ended up being the group to more successfully navigate the maze again. Franklin plans on surveying some of the children he treats, whose chemotherapy and radiation treatments also slow down hippocampus nerve growth, to test his theory.