Heritability is defined as the proportion of a manifested trait's varience that is due to genetic variation. Sixty-five pairs of twins were employed to investigate the heritability of: (1) short term memory (Jensen's Level 1), operationalized using of modified "digit span" test; (2) the general intellective factor (Jensen's Level II),…

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)

Pychologists, educators, and others have challenged the idea of a fixed IQ. This book uses recent research and earlier discoveries to argue that intelligence is not genetically set. Noting that the idea of learnable intelligence reflects the belief that intelligence can be taught, the book outlines a theory of learnable intelligence, including…