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),…

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…