The school leaving age regulations state: "Children may leave school once they reach their statutory school leaving date; this is dependent on date of birth. For children born between March 1 and September 30, it is May 31 of their fourth year of secondary school. For children born between October 1 and February 28, it is the last day of the December term of the school session in which they are 16."
It never ceases to amaze me how many of the children with the most challenging behaviour are in this latter group. In a recent visit to an off-site behaviour support unit, I was struck by the exceptionally high proportion of boys who were - or would be - "Christmas leavers".
It's interesting to relate this to the correlation between age and Standard grade attainment. There is a significant negative difference in attainment for boys who fall into the Christmas leaver category, whereas there is no such correlation for girls.
I can't think of any better evidence that early years education has an influence upon attainment in later years. Yet we continue to send children to school as young as possible. As a colleague recently commented on my learning log: "I have never been able to understand parents who send their kids, boys or girls, to school before they have to.
"But heshe is ready for school" is the usual refrain. It's nonsense. If kids are "ready" at four and a half to start school, they will be even more "ready" when they are five and a half.
To continue this link between early years and secondary school outcomes, it's interesting to reflect that many boys find themselves in the "bottom group" in their early primary years and, unfortunately, stay there throughout their school career. The move to active learning in early years is certainly countering some of this, and I'm greatly encouraged by what I am seeing in our classrooms. There is a much greater level of engagement in the learning process than had previously been the case.
Nevertheless, the gap in attainment between younger and older children does require that we think very carefully before allowing "young" children to commence their primary school education.
Recent research, and our intuitive understanding, into the link between the ability to read and the ability to access the curriculum would suggest that a child's developmental level is a key factor in their success or failure. Yet we treat younger children, who might be 20 per cent behind in their development, in exactly the same way as their peers. Is it any wonder that they struggle, disengage and seek displacement activities in their later years? If we don't get things right at the beginning, children are playing catch-up for the rest of their time in school - yet so many of them never catch up.
Don Ledingham is head of education in East Lothian Council.