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)

Changes in intelligence among Swedish 13-year-olds during a 20-year period was studied. Results show: (1) the average of spatial and reasoning intelligence has risen; (2) verbal intelligence increased during the 1960s, but declined thereafter; and (3) by the 1980s girls surpassed in verbal ability and equalled in spatial ability. (Author/LMO)

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)