State schools teach the basics of political/ethnic prejudice in the process of teaching history. National pride is not something that can be TAUGHT. It’s something you grow into by yourself. When you try to TEACH national pride, what you end up teaching is prejudice.
National history of every country should explicitly start with the following: We’re NOT the greatest nation on Earth. We’re NOT the most righteous people on Earth. We’re not the most clever. We may be ahead in some areas, behind in others, but we’re just another group of people just like everybody else.
Avoid things like: Glorification of past, bloody battles: History books meant for young children depict Dutugemunu as a hero in the Elara-Dutugemunu war. The same treatment is given to a number of other less-than-righteous kings.
If memory serves me, a Grade nine school history book mentioned with barely concealed glee, two notable defeats of Portuguese/British at the hands of Sinhalese militia. It specifically mentions how a certain lake/marsh turned red with the blood of the foreign soldiers: hardly an educational fact.
Many other interactions with foreign races have been recorded in our school history books in neutral sounding language, but with a definite Sri Lankan slant. The school books have been partially sanitized of most of the wrongdoings committed by Sri Lankans.
As Bertrand Russell says, if every country taught their own imperfections and non-superiority to their young, they will be less likely to approve state aggression against other ethnicities or groups. But such a public is a disadvantage to a power-seeking regime.