1. Development is lifelong, multidimensional, and occurs at varying rates in different areas for each individual. Early experiences have cumulative and delayed effects, and development proceeds toward greater complexity through interaction with the environment.
2. "Growth is evidence of life" or "development is evidence of life" means that continuous development and learning are signs that an individual or child is alive. It implies that people must continue developing throughout their lifespan through interactions with their physical and social environment.
3. Principle 8 regarding the interaction between biological and environmental influences on development, including the physical and social worlds, matches the characteristic of development proceeding through interaction with the environment.