Finland has the best mean sciences scores among the OECD countries while France is in the OECD average (PISA 2006). Nevertheless, when measuring interactions between knowledge and values in teachers' conceptions, the comparison between the two countries shows surprising results. In the context of the European research project Biohead-Citizen, in-service and pre-service teachers filled out a questionnaire including 31 questions related to the genetic determinism of human performances. The samples (732 in France, 306 in Finland) comprised Primary School teachers and Secondary School Biology and Language teachers. The answers to the questions dealing with only scientific knowledge, or with only social values, did not differ with the country. Nevertheless, there are very significant differences for the interactions between knowledge and values mainly related to innatism: for instance, Finnish teachers more agree with the proposition "there are genetic factors in parents that predispose their children to be good in school" (or "good violinists"); or with "It is for biological reasons that women more often than men take care of housekeeping". Our results are analysed with different statistical tests including multivariate analyses. They are then discussed, taking into account the respective content of school textbooks in the two countries.