A common word in the vocabulary of most people, development refers to change that is good and positive. It is a term often used to describe economic growth, improvements in social conditions and progress in the fulfillment of basic human needs. It is also a phrase commonly used to describe the growth of new technologies, and it can be used to discuss the progress that happens in an individual or a company.
As an academic field, developmental science or lifespan development examines the ways that people develop and how they remain the same, from birth to death. It is a scientific field that considers changes and stability in multiple domains, including physical and neurophysiological processes, cognition, language, emotion, personality, morality, and social relationships.
The field of development is guided by many assumptions about how people grow and change. These assumptions are called meta-theories and may include beliefs about how people behave, the role of their environment, and the causes of their development. They are often based on particular theories of human behavior such as behavioral genetics, sociobiology, ethological, neuroscience, temperament and personality theory.
For example, some researchers, like Piaget and Erickson, believe that everyone proceeds through the same stages of cognitive development in the same order and at the same pace, while others, such as those who endorse lifespan or ecological systems approaches, argue that different people negotiate a variety of different patterns and pathways of development depending on their unique experiences and environmental contexts.