There’s a moment when you introduce your new baby to his older sibling when you realize your toddler is not the squishy little ball of pudge that you thought he was, but is, in fact, a clumsy giant who is not to be trusted around your new little ball of pudge. You may be slightly freaked out by this discovery. And you may suddenly wonder why you are still changing diapers on this almost-adult being. In fact, it may occur to you that this child is so big that he hardly needs you at all.
At least, that is how it has been for me.
I’ve been through that moment twice. When my second baby was born, his tiny, helpless body contrasted so sharply with his older brother’s that I thought my 2-and-a-half-year-old must have grown several inches overnight. He was no longer the tiny toddler I had been coddling, but a child who was clearly not as dependent on me as I had thought. At least not compared to the new baby. Same story when my daughter was born nearly a year and a half ago: the little brother who had been a cute and helpless little boy just the week before grew up very suddenly into a lumbering giant of a child.
I assumed that the change in my children was all in my head. With a tiny new baby to compare them to, it is no wonder my toddlers suddenly looked much bigger. And while that is certainly part of the change in my perspective, it turns out that there is more to it than that: a recent study demonstrates that mothers consistently perceive their youngest children as smaller by a couple of inches than they really are.
The study, published in Current Biology and researched by psychologists at the Swinburne University of Technology in Melbourne, Australia, surveyed nearly 750 mothers and found that more than 70 percent of them felt their youngest child suddenly appeared much bigger after the birth of their new baby. And while this may be attributed to the contrast between the two children, there was no change in perception of any older siblings.
The researchers dug a little deeper to try to find out why only the youngest children were affected by this change-in-perceived-size, and not their older siblings. To test this, the researchers had moms mark on a wall the height of their children. Older children were consistently marked at nearly the right height — with less than an inch discrepancy between the mother’s “guess” and the child’s actual height. But the youngest child — the “baby” of the family — was consistently “guessed” to be much shorter than he or she actually was by about 3 inches. The older the child was, the greater the discrepancy between their actual height and their mother’s guess.
And while we don’t actually know the why precisely, we can theorize: it could be that moms perceive their youngest child as babies as an evolutionary adaptation to make sure they get the care they need the researchers call this “baby illusion.” And then, when the new baby is born, the illusion is broken and the mom really sees the child as a child, and not a baby, for the first time.
This finding was both humorous and comforting to me. Humorous because it rang so true. I remember clearly how my cute little boys were no longer little when they became big brothers. And I remember how I suddenly expected much more from them despite the fact that neither of them were 3 years old when the new baby was born. A part of me thought I might be going a little crazy with how protective I felt of the tiny little newborn when the big, clumsy toddler was around. I mean, how could I not have realized how big they were?
And that’s where the “comforting” part comes in: I wasn’t really going crazy to think that my child had grown 3 inches overnight, even if it was all in my head. And perhaps it is in my head for a good reason: so that my youngest and most helpless child gets the care he needs. Knowing that, I believe, will make it easier to keep a level head the next time I find myself with a newborn in my arms and an enormous toddler trying to worm her way into my lap and maybe help me remember that the toddler is my baby, too, and still needs my love and care.