Baby Illusion?

Now here's an article detailing a recent study of the "Baby Illusion".

'Baby Illusion' Makes Mums See Youngest As Too Short

The study asks moms to mark the height of their child on a chart without the child present.  The study shows that moms do very well at marking the correct height of their oldest and/or middle child, but fall 7.5 centimeters (about 3 inches) short when marking the height of their youngest.  Interesting!

I should test this out at home to see how close my wife and I are at marking our daughters' height.  My 3 year old is obviously shorter than my 6 year old...duh!  My 3 year old is also shorter than my 6 year old was at the same age by 1.5 - 2 inches.  So she really is shorter...at least at this point in her life!  I wonder if knowing that she's shorter at the same age will cause me to underestimate her actual height.  Hmm...