Explaining the success of the Finnish education system

It's a standard enough trope: the Finnish education system does very well so our education system should be just like the Finnish one. Meaning comprehensives for all and put the private education system to death. That is, of course, attractive to those who have been arguing for decades that we should put the private sector education system to death and have comprehensives for all. There's an interesting new paper arguing that it really might not be all that simple:

Finland has been noted to perform consistently very well in the international PISA assessments for many years, but it also has a relatively low per capita number of Nobel Prize winners. We draw upon a large body of proxy data and direct evidence, including the first ever use of RTs to calculate the Finnish IQ and the first ever use of the WAIS IV and PISA scores in the same capacity. Based on these data, we hypothesize that Finns perform so consistently well in PISA because they have a higher IQ overall than other European countries and exhibit a specialized slow life history strategy characterized by high Agreeableness and Conscientiousness, and low Psychoticism and Extraversion. Most of these traits predict educational success but all would suppress genius and creativity amongst this population.

If Finnish children are both brighter than those in other countries and also the culture itself supports conscientious hard work then yes, we might well think that that has an impact upon the success of the education system.