What is the relationship between childhood developmental delays and iq as an adult?

See below: It would depend on the type of delay. Children with speech delay, gross motor or fine motor delays, will more than likely have no impairment of intellect.

Dr Cordero and another doctor agreed

Close approximation: When children are old enough to have standardized testing, the scores will approximate the scores on standized IQ testing as an older child and adult. Be careful not to judge the development of children by motor developmental. There is little validity using only motor milestones. Language development is a better approximation of later intelligence.

Dr Willson agreed