Q.Describe the main features of life-span perspective on development.

Development is the pattern of progressive, orderly and predictable change that begins at conception and continues throughout a person's life. It is a broader idea than either growth or maturation, though it includes both as components. Growth refers narrowly to an increase in the size of the body or of a body part — something directly measurable, such as an increase in height or weight. Development covers far more than size: it applies specifically to changes that have a clear direction and hold a definite relationship with what came before and what comes after, which is why a temporary change caused by a brief illness is not considered part of development at all. Development includes not just growth in size but also changes in bodily proportion (the proportions of a child's body differ from an adult's), changes in features (such as the disappearance of baby teeth), and the appearance of genuinely new features and abilities over time. Maturation, meanwhile, refers to those changes that follow a fixed, orderly, genetically dictated sequence and appear to 'unfold from within,' largely independent of specific training or practice — for instance, most infants can sit without support by about 7 months and walk by about one year, and trying to accelerate this schedule through special training does not help if the infant is not maturationally ready, though appropriate environment and some ordinary practice are still needed once the underlying structures are ready.

Development itself arises from the interplay of three broad, always-interwoven kinds of processes. Biological processes are genetically driven, covering physical change in height, weight, and the growth of organs such as the brain, heart and lungs. Cognitive processes cover the mental activities of knowing and experiencing — thought, perception, attention, and problem-solving. Socio-emotional processes cover change in how a person relates to others, and in their emotions and personality — a child's hug for a parent or an adolescent's sadness at losing a match are both socio-emotional in nature. Although textbooks describe these three kinds of processes separately, in an actual developing person they are constantly interacting with one another, never operating along entirely separate tracks.

The Life-Span Perspective adds a further set of organising assumptions to this basic definition: development is lifelong (spanning conception to old age, and involving both gains and losses that interact dynamically); it is multi-directional (some abilities may increase even as others, such as speed on physical tasks, decline with age); it is highly plastic, though the degree of plasticity varies between individuals; it is shaped by historical/generational context, by the many disciplines that study it, and by the specific contexts — inherited traits, physical environment, social, historical and cultural setting, and individual life events — within which a person actually lives.