The results of our analyses concerning the characteristics of fertility behaviour of Slovenian residents may be useful tool for the policy makers dealing with social, family, population, defence, regional, border and health policies. Our findings can serve as a source of the basic information and expert background in population policy planning and in very concrete population measures. Reliance on experts' knowledge on population issues reduces the risks of well known "historical" mistakes in the population policy formation. Such policies originated from the inexpert understanding of fertility: from eugenics or exclusive/inclusive attitudes. This statement is best demonstrated through an illustrative example of knowledge misuse: an inexpert manipulation of fertility can lead towards an impermissible political banality, displayed as a stimulation of selective fertility among particular, mainly privileged groups within a certain state.