The culprit is primary science. Introduced through the Nuffield Science Project in the early 1960s, primary science continued having mega-bucks thrown at it through Science 5-13, Learning Through Science and the Scottish Primary Science Development Project. Each in its turn was welcomed as the way forward and enthused over by a generation of primary advisers.
Each in its turn stuttered to its end, producing a congratulatory evaluation report and a legacy of books and workcards to gather dust at the back of classroom cupboards.
The enthusiasm of the pilot projects did not communicate itself to the majority of teachers, most of whom continued to lack confidence, resulting in work which was tentative, half-hearted or non-existent.
Now, true to its tradition of attracting money, primary science is acquiring more grants, this time from the Scottish Executive. A fund of pound;270,000 is to be available to support projects at the primary-secondary transition stage. At the same time, the Scottish Science Advisory Committee is calling for increased investment in all areas of school science, emphasising the importance of the primary years and the worrying loss of interest between P7 and S2. But before even more money begins sloshing around primary science, we need to be clear about the problems, particularly at the upper stages.
Teacher confidence comes top of the list. Many had bad secondary school science experiences which colour their attitudes even today. They feel that their knowledge and understanding are lacking and they are baffled by practical activities which "go wrong". Then there is the problem of practical work in classes of 25-30 pupils. If secondary teachers won't attempt it, why do we think it will work at primary 7?
Curriculum organisation counts too. The revised 5-14 guidelines have provided a core of knowledge, skills and experiences which should ensure continuity and progression but they are useless if individual schools do not organise them into clear topics with resources and teaching materials provided. Science doesn't work when the teacher has to indulge in a time-wasting gathering of items in sufficient numbers for her pupils.
Frequent reports note poor continuity at transfer from P7 but unless there is a solid foundation at primary stages, we cannot blame secondary teachers for their lack of interest. We have to put our own house in order first. To begin with, the science establishment must stop patronising primary teachers and their very real problems. When we complain about lack of knowledge, we do not wish to hear the reply that it's the "process" which counts. "Tell the children to look it up," we are told, if they ask a tricky question. Not on. We know that knowledge does matter. Either we learn more ourselves or we train science co-ordinators whose expertise we can tap into.
The culture of integrated topics needs to be questioned too. The HMI document, Improving Science 5-14, and the revised environmental studies guidelines allow for standalone primary science - it's the most workable way that teachers and children can achieve a clear focus on science knowledge and skills.
The superb Improving Science website provides materials for a sound structure as well as addressing many of the class teacher's difficulties.
It can be found on the Learning and Teaching Scotland portal and is vastly superior to the terrors of its assessment site.
Peter Peacock, the Education Minister, wants to "ensure that primary teachers have better support in the provision of science classes". Let's hope that he's listening to them before distributing his money, or another 40 years of confusion awaits.
Brian Toner is headteacher of St John's primary in Perth.