This thesis Investigates the management of information about the biological origins of individuals conceived through the use of a third party; that is, by donated gametes or surrogacy. From a review of policy reports and academic studies of families created in this way, I identify three possible management strategies: complete secrecy; openness about the means of conception coupled with third party anonymity; openness about the means of conception, coupled with releasing the identity of the third party to the individual conceived, when adult. The middle strategy is exemplified by the Report of the Committee of Inquiry into Human Fertilisation and Embryology (the 'Warnock Report', 1984). This I explore in two ways: first through a detailed analysis of the Report itself, then through a series of in-depth interviews with committee members. I conclude that although the Report can be read as a prescription for the creation of 'normal families', in which the above management strategy on origins is a device for protecting ideologically-correct but biologically-anomalous families, from the interviews It appears that thie represented a suspension of more profound difficulties experienced by members when discussing these issues. These difficulties arose from what members found to be an Irresolvable dilemma over the contribution of biological factors to family life. In the final chapter I examine the nature of the contrast between the Report and the interviews; I then locate the above dilemma in broader theoretical debates and finally I suggest that the strategy of recommending anonymity between all parties exposes rather than resolves the tension between the 'biological' and the 'social' in everyday, lay, reasoning about family life. In the light of this conclusion I speculate on possible developments In the management of origins information and the likely impact of third parties being named In the future.