Abstract

Strong long-termism maintains that how we should act morally is determined almost entirely by the expected effects on the welfare of people living thousands if not millions of years in the future. It is based on three key assumptions: (i) that the welfare of future people is morally equally important as our own welfare; (ii) that there is a good chance that our descendants will vastly outnumber us; and (iii) that we can do things here and now that can be expected to have a positive impact on many, if not most, of these future lives. The aim of this contribution is to suggest that authors such as Will MacAskill and Hilary Greaves have been too optimistic about (ii) and (iii), and possibly also about (i), as a result of having ignored evidence that post-industrial societies are becoming less intelligent due mainly to increasing mutational loads and to the negative relationship that has emerged within these societies between intelligence and fertility.

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4707204