It is the teacher's responsibility to determine a student's prior understanding before moving onto higher levels. If the student is in a period of slower brain growth, new facts might be more effectively assimilated by presenting the material at levels which allow them to use their present intellectual skills. Teachers must strive to uncover student's misconceptions and try to correct them before moving onto higher level thinking skills. In the middle school, by the age of 11, most but not all, adolescents are at the beginning of formal operational thought. Most people will achieve their full range of cognitive capactiy during this age frame.
Adolescents can begin to understand abstract terms, synthesize, and analyze information.
However, most middle schoolers are concrete operational thinkers, some may even be pre-operational intuitive.