The milestones are guidelines and only guidelines. They are not IQ tests that can determine whether or not child is gifted -but they can be important checklists that parents and caregivers can use to be sure a child is on track.
My very typical dd (read that average), reached almost every mile stone very very early. I was convinced she was going to Harvard. My 2-E son did not know his alphabet until he was 8, could not recite the months of the year until about the same time. He still mixes up his zip code at age 14. Yet, he is the one with high "intellectual horsepower" as measured by WISC IV. These check lists helped us to understand that we needed to get more data about his development, and we learned that in addition to his intelligence, he has some glitches in his learning profile that needed to be addressed.
As someone else noted - toddlerhood is marked by some amazing and uneven growth spurts. The milestones are guidelines and "normal" is defined by the bell curve of a random sample. Parents can be proud and breathe a sigh of relief when their kids are on track, or even ahead of the curve. Sometimes kids stay ahead of the curve, sometimes their peers catch up. But, don't underestimate the abilities of your neighbor who might be slower to meet milestones. Sometimes the turtle wins the race.
