The objective of this paper is to analyse the intergenerational transmission mechanisms within a theoretical framework which presumes a heterogeneous family structure. For that, we propose a modified version of the Becker and Tomes model (1986) by assuming that there are two groups of children: the elder and the juniors. We try to see how according to the elder achievement, the parents modify their choices of education or of training for the juniors given returns and endowments.