I believe that there are many kids who do look very advanced as newborns, and they actually DO "even out". I'm sure there is a correlation between infant developmental milestones and later cognitive ability, but it probably isn't very strong or predictive. Both of my kids scored 99th percentile on the WISC-IV and both looked pretty average as newborns/young infants. Neither one of them really took off in any obvious way until age 2-3 (and that could have been because of environmental influences). They are 100 percent genetically UNrelated, but have remarkably similar IQ scores, even down to specific subtests. Both of them had Picture Concepts and Matrix Reasoning as their highest scores, and coding as their lowest score. DS was a somewhat early walker, and then he ended up with a developmental coordination disorder diagnosis a few years later. I've seen kids who did everything early as infants, and they are now average, or even behind.