According to the latest findings published in Current Biology, birth order may affect how our bodies are perceived. It makes everyone mistakenly think that the youngest in the family appear smaller than they really are.

Researchers from Swinburne University in Melbourne got mothers whose kids were in the 2 to 6 year old range and asked them to estimate how tall they were by marking a featureless wall, and then compared them to the actual height of each child.

Moms came close to guessing children with younger siblings, but when they were guessing the heights of the youngest in their family, they fell short of an average of three inches. The researchers also conducted an online survey of 747 mothers, 70% of which confirmed that their first child looked much bigger after birth compared to their second child.

The researchers theorize that this could be why "baby illusion" takes place because “exaggerating the smallness of the younger child [...] would help parents to more readily distinguish relative age and importance of care at a perceptual level and allocate resources accordingly.”

Are you a mother with more than one kid? Does this happen to you?