The study of human development, or lifespan development as it is sometimes called, examines both the ways we change and the ways we remain the same from birth to death. It is the scientific field that looks at changes in multiple domains of human functioning, including physical and neurophysiological processes, cognition, language, emotion, personality, moral and psychosocial development, and our relationships with others.
A person’s development is influenced by many factors in the environment, a process known as context-dependent development. Many of these influences are cultural and historical in nature. Some researchers, such as Piaget and Erickson, believe that people progress through the same cognitive developmental stages in a universal manner. Other researchers, such as those who have embraced the life-span perspective on human development, have a more contextualist view and have emphasized that developmental pathways are unique to each person.
Similarly, many scholars have a diverse view of what it means for a country to be considered developed. Some, such as Nobel Prize winner Amartya Sen, have embraced the capability approach, which defines development as a tool that allows individuals to reach their highest level of well-being by granting them freedom to choose their own economic, social and family actions.
Finally, some researchers have a mechanistic meta-theory of development, which views humans as if they are machines that change in the same way that machines do. Those who hold this belief have used the metaphor of gas and brakes to illustrate that humans are passive, changing only because their external environments cause them to react (like a car responding to the pressure on its gas pedal or brake). Other researchers have argued that a person’s development is more complex than that simple metaphor allows.