Analysis of the desire for children has become topical once again in demographic research, as a number of industrialized countries are experiencing low fertility, and ageing has become a matter of concern almost everywhere in the world. In the previous issue of Population , Maria Rita Testa and Leonardo Grilli examined the influence of the fertility context in European regions on the desire for children. Arnaud R ÉGNIER -L OILIER turns here to the influence of family background on the emergence and variation of preferences during family formation. His longitudinal perspective on varying preferences over the life course comprises carefully selected survey data and interviews, showing how little the desire for children predicts actual family size.*Institut national d'études démographiques. Translated by Roger Depledge.(5) The same people were surveyed again in 2001 and 2003. However, because of the small sample size for the final survey (N = 783) and problems of selective attrition (Mazuy et al., 2005), these data could not be used for the analysis.(6) For a description of the survey, see Cassan et al., 2005.Population: Women aged 45 living with a partner and men whose partner is 45.