A researcher tested the IQ of 12 to 16-year-olds in 2004 with a score of 77-135  Four years later, they scored 87-143  Instrument scans showed that students with higher scores showed more gray matter (a nerve tissue that is an important part of the central nervous system) in their brains than before
The poor early performance of some students in school is related to their IQ
 The test shows that individual IQ changes do exist, and students who do not perform well in school at an early stage are still likely to be outstanding in the future