Do grown up children have obligations to their parents? Do the younger members of a society have obligations to their elders? Most people think that the question in both cases is answered by an appeal to the benefits which those now old conferred on the young. Janna Thompson argues that the duties of the young to the old are truly intergenerational responsibilities - and not cases of delayed reciprocity. The people of each generation fulfil obligations to their elders and reasonably expect to be cared for in their turn by their children or other members of younger generations.