On UK Teacher Twitter, there are two factions that disagree noisily but civilly: the 'trads' and the 'progs'. Both factions have educational psychology research to back up their claims: the progs lean mainly on research from big institutions, often international; the trads often do research in their own classrooms. The trads' pupils seem to do better in the UK's public examinations, but that might be an artefact of those exams.
It's also worth noting that half of all teachers leave the profession leave within five years. Forty years thus represents about eight generations of teachers being trained with their own biases, refining their ideas in classroom practice, and then training the next generation. On top of this are the cycles of trendiness in the various schools of thought in educational psychology, as well as the varying policy platforms of governments. Educational practice from four decades is less historical and more archaeological.
It's also worth noting that half of all teachers leave the profession leave within five years. Forty years thus represents about eight generations of teachers being trained with their own biases, refining their ideas in classroom practice, and then training the next generation. On top of this are the cycles of trendiness in the various schools of thought in educational psychology, as well as the varying policy platforms of governments. Educational practice from four decades is less historical and more archaeological.