I have long been intrigued by the fact that I can sometimes tell that a child is of very high intelligence, even when I do not know the age of that child, and therefore have no basis for age-adjusted comparisons - and this sometimes happens when the child is not a prodigy, and has no exceptional ability. There is something about them that lets me know that they are of exceptional intelligence.
If intelligence is conceptualized as merely the upper range of a normal distribution curve of intellectual ability, then this should not be possible (except when the child's current ability is prodigious).
I have always assumed that being able to detect an intelligent child meant that what was truly being detected was not intellectual ability but personality; and I now think that what is being detected, what is detectable from early childhood, is the Endogenous personality.
The Endogenous personality is a package of high intelligence and a type of personality designed (by evolution) for creativity; in effect what is being detected is that the child has a brain specialized for a genius type role. What is being detected is not really the high intelligence so much as the other two aspects of the Creative Triad of high intelligence, inner-motivation and intuitive personality
In most children with high intelligence, their intelligence is only observable by making age-adjusted comparisons of their cognitive abilities because they have all different kinds of personality types.
But in the minority of children who are Endogenous personality types, the intelligence is part of a cluster of traits, and can be recognized from an early age - indeed, people with experience of a range of children (e.g. astute good school teachers) can recognize the Endogenous personality in young children at, say, six or seven years old.
In a sensible world, such children would be noticed, and treated as the different kind of people they are: people with some kind of creative destiny that, if discovered and allowed to develop, could benefit the rest of society.