Subdivisions of the Life Span
Regardless of how long or how short the total life span is, it is usually subdivided into stages or periods, each of which is characterized by certain behavioural or developmental characteristics. Chronological age (C.A.) is the criterion used for this subdivision. As Fry has explained:
C.A is only a rough index of biological, psychological, sociological, and cultural aging processes. Yet C.A. continues as the principle criterion for determining age categories on the part of bureaucratic organizations and in a wide variety of research. … Cultural age categories are determined on the basis of events in human society which in effect are “social clocks.”
Each individual goes through a succession of developmental stages, though at different rates and at slightly different ages. However, to quote Fry again, “Age is an index positioning individuals in a developmental sequence”.
All cultures divide the life span into periods, although different names are given to the periods and the age levels encompassed by the different stages vary. Even in the American culture there are variations. Erikson, for example, has subdivided the life span into eight stages with the following labels and basic components: infancy, the stage of trust versus mistrust; early childhood, autonomy versus shame and doubt; preschool age, initiative versus guilt; school age, industry versus inferiority; adolescence; identity versus identity confusion; young adulthood, intimacy versus isolation; adulthood, generativity versus stagnation; and senescence, ego integrity versus despair. As may be seen, Erikson contends that each stage has two possible resolutions, positive and negative. Failure at any stage adversely affects later stages.
Today it is customary to subdivide the life span into ten stages or periods, each with certain developmental and behavioural patterns. These are shown below:
Stages in the Life Span
- Prenatal period: conception to birth
- Infancy: birth to the end of the second week
- Babyhood: end of the second week to end of the second year
- Early childhood: two to six years
- Late childhood: six to ten or twelve years
- Pubertyor preadolescence: ten or twelve to thirteen or fourteen years
- Adolescence: thirteen or fourteen to eighteen years
- Early adulthood: eighteen to forty years
- Middle age: forty to sixty years
- Old age or senescence: sixty years to death
Not all individuals reach these stages at the same time and not all pass through all of them. Some people die or are killed before they complete the normal life span. But each stage has problems that must be solved before the individual can progress to the next stage. Failure to do so results in immaturity and poor adjustment. The remaining chapters of this book will discuss in detail the characteristic patterns of behaviour for each of these age periods and the reasons for any deviations from the predictable patterns. They will also explain the meanings of the names applied to each of the major periods in the life span.
Recent Focus of Interest in the Life Span
To understand the pattern of development from conception to death, one must have a picture of this that is based on the results of scientific studies, not on traditional beliefs and stereotyped ideas. However, as was pointed out earlier, many obstacles confront the developmental psychologist in the study of the various stages in the life span, and as a result there are gaps in our knowledge. Today there is almost as much scientific interest in the later years of life as there is in the early years, but attempts to study the later years have been blocked, in part at least, by obstacles which are only now being minimized and in some instances eliminated.
Interest in the latter part of the life span is not of recent origin. Hippocrates treated illness of old age, and there are also historic references to beauty aids for the elderly and to attempts at rejuvenation. However, until the turn of the present century too few people lived long enough to make the latter part of life a serious problem. Now an increasing percentage of the population lives longer, and this has created many problems for the individuals themselves and for their families, their employers, and society in general.
As a result, two new areas of scientific research have been developed – gerontology and geriatrics. Gerontology is the science of aging. It is derived from the Greek geron, meaning “old man,” and ology, meaning “the study of,” and it is concerned with all facets of aging. Geriatrics, on the other hand, is that branch of medicine concerned with the diseases of old age. It deals with the health of the aged, just as paediatrics deals with the health of infants and children.
The major goal of studies in the area of gerontology is to gather data to disprove traditional beliefs about the aged and to show how they can function successfully in a youth-oriented culture.
To prolong the usefulness and happiness of old people through better health has been the goal of geriatrics. While improvement in the health of old people may and often does add years to their life span, this is of little value unless individuals are able to enjoy and make use of this added time not only for their own enjoyment but also to aid society. The goal of geriatrics is therefore to add life to the years of the elderly, not just years to their lives.
Middle age, until recently one of the least explored periods in the life span, has now come under scientific investigation.
The reason for this is that few problems related to middle age seemed important enough to engage the attention of the psychologist, who was already preoccupied with studies relating to children, adolescents, young adults, and old people.
Not only has there been increasing scientific interest in the latter years of life, but there is also a strong popular interest in the subject, as evidenced by the appearance of many books and articles dealing with the problems of middle and old age.
