Physical evidence please? There exist clear physical indicators that children are moving out of one stage of development and into the next stage. The stages last from birth to seven; from seven to fourteen and from fourteen to twenty-one.

The physical indicator of the child moving from the second to third stage is puberty and this is obviously well documented, no doubt because of the effect of this period on those adults in close proximity to the adolescent!

The physical indicator that the child is moving from the first stage to the second stage is the change of teeth; very little evidence and documentation exists on this physical change.

Two qualifications need to be made. The first is that there occur further subdivisions and these will be described in other descriptions on child development. Secondly, we are going to describe the stages as separate from each other. It is obvious, however, that a child does not move from one stage to another overnight so to speak.

The changes occur gradually over long periods of time; some changes taking many months – some even longer. What do you think?