There are 3 general principles applied to all forms of development (Berk, 2013; Boyd & Bee, 2012; Feldman, 2014). What are they?

1. Development depends on both heredity and environment. Heredity interacts with the environment, through the experiences we provide, to maximise development. 2. Development process in orderly and predictable pattern. Development is relatively systematic and predictable. For example, we babble before we talk, crawl before we walk, learn concrete concepts before abstract ones. These patterns exists in virtually all human beings. 3. People develop at different rates. While development is generally systematic and orderly, the rate at which individual progress varies. "He's a late bloomer". These differences influence the effectiveness of our instruction and our interaction with our students.