The Life-Span Perspective on development is based on the primary assumption that development is lifelong. It takes place across all age groups, starting from conception to old age. This perspective emphasizes that development includes both gains and losses, which interact in dynamic ways throughout the life-span.

Development involves an interplay of biological, cognitive, and socio-emotional processes. These processes are interwoven and influence the development of a person throughout their life. Additionally, development is multi-directional. This means that some dimensions or components of development may increase, while others show a decrement. For example, while adults may become wiser with experience, their performance on tasks requiring speed is likely to decrease with age.

Another key feature is that development is highly plastic. This indicates that modifiability is found in psychological development, meaning skills and abilities can be improved or developed throughout the life-span, though plasticity varies among individuals. Development is also influenced by historical conditions. For instance, the experiences of 20-year-olds who lived through the freedom struggle in India would be very different from the experiences of 20-year-olds today.

Finally, development is the concern of a number of disciplines. Different disciplines like psychology, anthropology, sociology, and neuro-sciences study human development. It is also contextual, meaning an individual responds and acts on contexts, which include what was inherited, the physical environment, and social, historical, and cultural contexts. Life events such as the death of a parent or an accident also affect the course of one's life.