Abstract
Performance and ability to learn in old age seem to depend not only upon physical and mental capacities, but upon willingness to use these capacities fully. This paper outlines a possible model of such a process, in terms of two known principles of motivation: first, that willingness to undertake action is a function of some difference or ratio between expected result and the effort, whether physical or mental, required to attain it; and second that what is achieved is valued more highly if the effort required has been relatively great. These principles seem capable of tying together many seemingly disparate facts about age changes in learning and in adaptation to developments at work, and also in everyday interests and pursuits and in the acceptance of rehabilitative procedures. They also have implications for human relationships in old age. These are discussed with reference to loneliness, which is regarded as arising when personality characteristics make communications from and to other people unrewarding.