London - It seems the baby of the family never grows up – at least in their mother’s eyes.
A study found that mothers routinely underestimate the height of their youngest child, in a phenomenon that may also explain why an older brother or sister often seems to grow up overnight on the birth of a sibling.
The Australian researchers began by asking more than 700 mothers if their child had suddenly seemed bigger on the birth of a brother or sister. More than 70 percent said this was the case.
To work out why, the Swinburne University of Technology team asked a second group of women to estimate the height of one of their children and mark it on the wall.
The children, aged between two and six, were then measured and the results compared with the estimates. Mothers got the height of elder children roughly right, but underestimated the height of their youngest children by three inches on average.
Study author Jordy Kaufman said: “The key implication is that we may treat our youngest child as if they are actually younger than they really are.
“Our research potentially explains why the “baby of the family” never outgrows the label. To the parents, the baby of the family may always be ‘the baby’.”
The researchers say their results shows the perception that the eldest child suddenly appears bigger on the birth of a second child cannot simply be explained away by everything looking big compared to the newborn. Instead, parents seems to be subject to a “baby illusion”, in which they perceive the youngest child as being more fragile than he or she really is, and so the older child instantly seems bigger.
The study’s authors said: “This isn’t happening just because the older child looks so big compared to the baby, it happens because all along the parents were under an illusion that their first child was smaller than he or she really was. When the new baby is born, the spell is broken and parents see their older child as he or she really is.”
The journal Current Biology reports that the mental trick could be nature’s way of ensuring the youngest child gets the care it needs when it is at its most vulnerable. However, the perception may last for years. - Daily Mail