Psychological studies of aging: their origins, development and present challenge.

Present day psychological studies of aging had their origins in attempts to study, in fundamental terms, performances of people in later middle-age relevant to capacity for industrial work. From these beginnings fundamental psychological knowledge of aging has expanded rapidly during the last forty years. Application of this knowledge to practical problems presents a challenge and a wide field of opportunity. Needs and potentialities for application are considered in the areas of: Industrial and other work, Clinical assessment and intelligence testing, Assessment of attitudes, and Coping with everyday problems in old age and with interpersonal relationships, especially in old people's communities and between old people and caregivers.

Preventing adverse changes of work with age.

Many people who change their jobs in middle age have been found to move to less skilled and lower paid work. Two methods of preventing this are discussed. First, training by methods designed to take account of learning difficulties in those past normal apprenticeship age has, when sensitively applied, been successful in equipping people with new skills. Second, applying principles of ergonomics--"fitting the job to the worker"--could often remove key difficulties for older workers and thus prevent the need for moves resulting from failing capacity. This could also open up a wider range of potential jobs for those who have to move by reason of redundancy or technological change. It is emphasized that both the training and ergonomic approaches need to be based on, and can contribute significantly to, fundamental research on performance in relation to age.

On rates of improvement with practice.

A survey of practice effects for several sensory-motor tasks shows that no one linear equation relating performance time to practice gives a good description of them all. However, most of the data are well described in terms of equations derived from signal-detection theory, which postulate that, during each trial, activation of a correct response has to be made to an extent that it is discriminable from others. The activation is built up in part during the trial concerned and in part from a carry over from previous trials. In some cases, practice effects are proportional to the time taken by the first trial, but in others they are not. The question is considered of whether effects should be treated in terms of trials or of time. The extra information gained by comparing the regressions for two or more conditions in a task or for groups of subjects, rather than looking at one alone, is noted.

Forty years of experimental psychology in relation to age: retrospect and prospect.

Experimental psychological research on performance in relation to age is outlined to show how aims, methods and interests have developed between the pioneering days of the 1940s and the present time. More detailed consideration is then given to the actual and potential applications to studies of aging of the quantitative methods of Information and Signal Detection Theories, and to the importance of taking account not only of correct performance but of the frequency and nature of errors if age changes are to be fully understood. Research in relation to age on continued performance is discussed, including short-term serial effects and the longer terms effects of fatigue, learning and practice, and the need for further research in these areas is emphasised. Guiding principles for future psychological research on aging are briefly urged.

Between bodily changes and performance: some possible reasons for slowing with age.

A number of models are outlined which attempt to account for relationships between various bodily, and especially neural, changes and the widespread slowing of performance observed in old age. Muscular and neuromuscular changes can account for some types of slowing, but most types are attributable to central mechanisms. The accumulation of small increments of time in a long chain of cells from sensory input to motor output is shown to be an inadequate explanation. Correlations between reaction time, EEG alpha cycle-time and age are in line with the widespread tendency for increases of reaction time with age to be proportional, but do not take account of errors. A powerful model which does consider both time and errors is derived from the fact that signals from sense organs and within the brain have to be distinguished against a background of random activity ("noise") both in the signals themselves and in the central nervous system, and slowing of performance with age results from a fall in signal-to-noise ratios. This leads in some circumstances to absolute and in others to proportional increases of time taken by older people. Interacting with these factors are tendencies by older people to adopt higher criteria for responding, and to spend more time monitoring their actions. Certain cases in which there is a disproportionate increase with age of time taken appear to occur when memory is involved in holding data temporarily while other data are gathered to arrive at a decision. The several stages of information processing from input to output are affected by slowing with age differently in different tasks, so that detailed study of various aspects of tasks is needed to account for overall effects observed.

Social skill and aging: principles and problems.

Over the last two decades it has become increasingly recognized that concepts of skill, formulated originally for sensory-motor tasks such as industrial operations, can be applied to interaction between people. The need for social skills in the interactions between old people, their contemporaries, and younger people with whom they have contact, are explored, and suggestions are made for training social skills in order to improve human relations with and between the elderly. It is also argued that present ideas, favoring opportunities for older people to live in communities with those of like mind, can lessen the need for social skills by reducing the social demands of institutional living.

Desire for attention.

Seeking of attention appears to be intimately bound up with certain principles of motivation, especially the seeking of observable results of action and of optimum levels of stimulation, variety and challenge, and the relationship between results and the cost of achieving them--a high cost will tend to inhibit action but enhance the value subsequently placed upon what is achieved. These principles can be applied to personal relationships: thus friendship can be regarded as a situation involving facilitative feedback between persons, hostility as involving inhibitory feedback and lonliness as occurring when there is no feedback. Which of these situations occurs appears to depend upon the relationships between the costs and benefits of interaction between the persons concerned. The care of psychiatric or senile patients in the community appears likely to impose demands for attention which are unreasonably severe ("costly"). Any attempt to change community attitudes in the hope of securing greater acceptance of such demands appears to be unrealistic. Substantial benefits could probably be attained in many cases from training in skills, especially social skills, which would enable patients to cope more effectively with the world as it is.

Motivation, capacity, learning and age.

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.