School achievement and school adaptation in children in relation to CNS development as assessed by a complex reaction time measured on school entry--a follow-up.

Schoolchildren aged seven years underwent a complex reaction time (CRT) measurement and were followed up regarding language achievements and performance in gymnastics during the nine years of compulsory school. An analysis was made of the correlation between school results and CRT findings. In grade 3, there were large differences in psychomotor development between children with fast and slow CRT in both sexes. Only minor differences in school achievement were seen between girls in different CRT groups. Among the boys, however, many with a slow CRT were considered handicapped in language development, with dyslexia as the most important problem in addition to poor motoricity. They left compulsory school with poor results in Swedish, their native language, and gymnastics, and with a certificate that may reduce their changes of future studies and employment. The boys in general were inferior to the girls. The slow CRT boys, who were mainly considered to be developmentally delayed, also carried a risk of social maladjustment. It would appear to be important that psychophysical maturity receives attention at school, in addition to emotional and social factors. The school health services have an important responsibility in this respect.