Book excerpt: A unique feature of human development is that mothers and fathers are bound to a long period of child-rearing, during which the continuity of our species depends on the fulfilment of distinct parental roles and on the suppression of psychological potentials that conflict with those roles. But once the parental emergency is over, the author argues, men and women can assert those parts of their personalities curbed by the restrictions of raising children. It is this shift in roles - a product of evolution found throughout our species - that led David Gutmann to propose a new psychology of ageing, based not on the threat of loss but on the promise of important new pleasures and capacities.