About 85 percent of brain development has occurred by now, including intellect, personality and motor and social skills. A child’s brain has twice as many synapses as an adult’s brain. In a process called pruning, the neural connections that are used and reinforced most often—like those used for language—are strengthened, while the ones that are not utilized as much fizzle and die. (That’s why parents are often encouraged to repeat certain activities, like reading books, with their kids every day.)
This period of brain growth marks the beginning of a person’s ability to do problem solving, think critically, plan, and control impulses. This brain development cycle also impacts short-term memory. A middle school student can generally retain from 5 to 7 bits of information at one time, so teachers should not try to cram too much information into one lesson. The more engaged and “rich” the new information, the more likely it is that the new information will be retained. The short-term memory maintains information until it moves into another area of the brain (long-term memory) or until more, new information is introduced. At this point the short-term memory ignores the new information in favour of the previous information, or discards the previous information in order to deal with the new.