Comparison of the mental status of 30 subjects with Down's Syndrome mosaicism and 30 matched subjects with trisomy 21 Down's Syndrome found that the mean intelligent quotient of the mosaic Down's Syndrome group was significantly higher and that this group showed better verbal abilities and more normal visual-perceptual skills. (Author/DB)

A study of twins was conducted to determine the presence of an hereditary component in short term memory and in three aspects of verbal divergent thinking--flexibility, fluency, and originality. Results showed the existence of a significant genetic component in the trait of short term memory, while none was found in verbal divergent thinking. (AG)