Continuity and discontinuity are two competing theories in developmental psychology that attempt to explain how people change through the course of their lives, where the continuity theory says that someone changes throughout their life along a smooth course while the discontinuity theory instead contends that people change abruptly. These changes can be described as a wide variety of someone's social and behavioral makeup, like their emotions, traditions, beliefs, habits, personality and so on.
Furthermore, continuity and discontinuity disagree with one another in how they assess the changes that someone undergoes throughout the course of their life. The continuity theory examines the way someone changes in a quantitative and continuous respect. Discontinuity theory, on the other hand, looks at these changes through the lens of a qualitative analysis with an emphasis on the discontinuous nature of how someone changes.
Developmental psychology encompasses a very wide array of observations related to how people think, behave and interact with their environment as well as other people. This field, at first, was focused on how young children develop but, in recent years, it has expanded past the pediatric setting to encompass studies of how people change throughout the course of their entire lives, up until the point of their death.