Despite earlier claims that language abilities are intact in individuals with Williams syndrome (WS), many studies have shown that language development is often delayed and atypical, that is, it develops in line with different cognitive abilities compared to typically developing populations. It is unclear, however, whether general cognitive…

Individual differences in number sense correlate with mathematical ability and performance, although the presence and strength of this relationship differs across studies. Inconsistencies in the literature may stem from heterogeneity of number sense and mathematical ability constructs. Sample characteristics may also play a role as changes in the…

A meta-analysis is presented of 57 studies of sex differences in general population samples on the Standard and Advanced Progressive Matrices (SPM and APM, respectively). Results showed that there is no difference among children aged 6-14 years, but that males obtain higher means from the age of 15 through to old age. Among adults, the male…

A study of the responses made to problems selected from Raven's Progressive Matrices showed differences in the kinds of errors typically made by eighteen-year-old students. Nine problems were used and the 68 subjects were told to draw their answers on the answer sheets. There were two trials per puzzle. A classification system, devised for errors,…

A task was developed to differentiate the reasoning of elementary school students in fifth, sixth, and seventh grades. Subjects completed 16 matrices containing two, three, or four dimensions and varying in the embeddedness of the dimensions. They also solved a formal operational task assessing ability to isolate, exclude, and include variables.…