1, the individual's physical and mental development is unbalanced. This is mainly manifested in two aspects: first, the development speed of the same thing at different ages is uneven; The second is the imbalance of development in different aspects.

2. Personal physical and mental development is orderly. From birth to adulthood, the individual's physical and mental development is a continuous development process from low to high, from simple to complex, from quantitative change to qualitative change.

3. Personal physical and mental development has stages. Each stage of physical and mental development has different development contradictions, faces different development tasks, and adjacent stages change regularly.

4. Fourth, the individual's physical and mental development is complementary. After the function of one aspect of the body is damaged or even lost, it can be made up by the extraordinary development of other aspects. At the same time, this complementarity also exists between psychological function and physiological function. People's spiritual strength, will quality and emotional state can all regulate the whole body.

5. Differences in individual development. This refers to the individual differences in physiological and psychological characteristics due to the influence of heredity, environment, education and oneself.