The main objective of this paper is to show to what extent and why students with the same academic aptitude but different social backgrounds have different odds of entering university. We separated primary and secondary factors of social origin in the formation of educational inequalities as defined by Boudon (1974).
Primary factors include the socio-economic status of the family, the respondent's sex and his/her academic abilities, while secondary factors primarily comprise aspirations for further study. We used data from the longitudinal PISA-L survey, which enabled us to monitor young people's decisions concerning their educational career at the ages of 15 and 19.
The results of the conducted analyses show that the primary and secondary factors have approximately the same influence on the transition to university. As far as primary factors are concerned, the social status of the pupil's family and his/her academic aptitude have the most pronounced effect.