According to the theory of ideational shifts [Preston 1986], the growing spread of new forms of life as a couple may be attributed to the increase in individual autonomy in the ethical, religious and political field, i.e. to changes in the scale of subjective values. The cultural dimension influences the acceptance and experimentation of the different forms of union in a different way for the man and for the woman. The importance at the explanatory phase of taking account of ideational factors in addition to economic ones has been discussed in depth and demonstrated in the case of certain countries of central Europe by Lesthaeghe and Moors [1996]. And it is the framework of Lesthaeghe and Moors which we take as our starting point in this study, for the analysis from a gender perspective of the role played by value orientations in the choice of the various forms of life as a couple, marriage and cohabitation, in certain areas of Europe. In particular, cohabitation will be taken as representing that type of partnership which, at least theoretically, is associated with a reduction in gender differences: indeed, the absence of pre-established roles for the partners should render the relationship within the couple more egalitarian and free. Moreover, in consideration of the fact that the various European countries exhibit a distribution of types of union which is extremely differentiated [Kiernan 2000], we wish to assess whether there is any corresponding existence of similarly differentiated ideational factors; indeed, we cannot necessarily assume that the same value orientations lead to similar patterns of behaviour [Lesthaeghe 1998].