A follow-up study was performed to investigate the stability of IQ measures in a group of dyslexic teenagers and young adults. Earlier research had shown contradictory results. The 65 subjects, 12 years old on the average at first test, were retested after a mean interval of six and a half years. There was a significant relative decrease in…

Using data from the Swedish Individual Statistics Project, changes in intelligence among 13-year olds are documented over a 25-year period. The average spatial and reasoning intelligence has risen successively. A clear increase is found for verbal intelligence in the 1960s, with more irregular growth since then. (SLD)

Among 800 Swedish 13-year olds of high mathematical or verbal ability, boys with high verbal ability were found to have highly educated parents. Girls of high mathematical ability had high father presence and highly educated mothers. Educational choices in secondary school were more affected by gender than by ability. (SLD)

Changes in verbal, spatial, and reasoning intelligence among Swedish 13-year olds were studied from 1960 to 1990. Rising verbal scores until 1980 have been followed by a decline to essentially the 1960 level. Spatial and reasoning results have risen continuously. Gender and social class differences are discussed. (SLD)