ABSTRACT
Of the many challenges of demographic change one is particularly intriguing: the question of whether the human lifespan is fixed or plastic. It is a surprisingly complex question that is hard to tackle because conclusions cannot be drawn about the species from individual longevity. While religious thinking and common knowledge assume that ageing is inescapable and the limits to life are preset – for which there is a lot of inductive evidence – the scientific community is divided on the issue. Some insist that the length of human life is genetically determined, while others argue that it is subject to external influence and thus open-ended. The fact that irrefutable evidence for either position is wanting is not just theoretically fascinating, but also adds to the general uncertainty of life on this planet and poses very practical problems, for example, in actuarial circles and for health-care providers.
