First, the development speed is unbalanced, and the changes in different age stages are uneven. For example, at different ages, the development speed of height and weight is different.

Second, the development in all aspects is uneven. For example, some aspects reach a more mature level of development at an earlier age, while others reach a more mature level at a later age.

Take different countermeasures.

The characteristics of two aspects of unbalanced performance tell us that we should seize the critical period or the best period of individual development and promote individual development. The critical period of development refers to the period when the function and ability of a certain aspect of body or psychology are most suitable for formation. During this period, the best results can be achieved by training individuals in certain aspects. If you miss the critical period, the training effect will be reduced or even irreparable. Pay attention to different aspects of development.

However, according to the law of individual physical and mental development, education should adapt to the individual differences of the younger generation's physical and mental development and teach students in accordance with their aptitude. In the physical and mental development of the younger generation, there are individual differences in their physical and mental development due to differences in heredity, environment, education and their own subjective initiative. Education should pay attention to students' individual differences, teach students in accordance with their aptitude and be good at saving losses, so that every student can develop.