Internationally famous for its supposedly excellent education system and top-ranking Pisa results, Finland is reeling from new research that shows a dramatic decline in learning and cognitive ability among 15-year- olds.
Their educational competence has deteriorated by 25 per cent in the past six years, according to research carried out by the Centre for Educational Assessment at Helsinki University.
Fifteen-year-olds at schools in Vantaa, near Helsinki, were given tests that measured both cognitive ability and the skills needed to learn.
According to Sirkku Kupiainen, who was part of the research team, all forms of cognitive ability and evidence of the potential to learn have declined by about a quarter in six years, with the decline among girls slightly sharper than among boys.
Mrs Kupiainen stressed that the results were almost certainly applicable to the whole of Finland. "Vantaa is normally representative of Finland in education tests," she said. "It is likely that the same results would also be found elsewhere.
"We don't know if this reflects a decline in competence or a decline in the willingness of pupils to take the tests seriously," she continued, adding that these were not "high-stakes tests" that would have an impact on pupils' lives.
Nevertheless, not taking the tests seriously would indicate a shift in attitudes to education.
Finland has traditionally valued education and it has been a significant part of social status. According to Mrs Kupiainen, "this climate to learning may be changing", but "even so this is a much bigger decline than we would expect".
For the team, demographic changes in Vantaa, which has a population of 200,000, do not explain the deterioration.
"Vantaa has a very small percentage of pupils whose mother tongue is not Finnish, and when we factored these pupils out it actually made the decline bigger."
There is also no evidence that Vantaa has become more socially segregated, with pupils from more affluent backgrounds concentrated into certain schools.
"This is true in Helsinki, but Vantaa is the exception. It is the only large city in Finland where differences between the schools are still very small. Vantaa is one of the least economically polarised cities in Finland," explained Mrs Kupiainen.
Jorma Kuusela, a senior researcher for the Finnish National Board of Education, told YLE (the Finnish equivalent of the BBC) that, to explain the decline, he "would first go looking for reasons that have to do with the appreciation of school, finding school important, and the support that children get for going to school".
But for Mrs Kupiainen it is far too early to speculate on explanations. She suggested a nationwide test to ensure this was not a freak result, and stressed how "misleading" it is to regard the Finnish education system as successful solely on the basis of Pisa assessments.
"We are very good readers and Pisa tests are about written problems so this gives us an advantage. We also have an advantage because our language is phonetic," she added.