Research has shown that differences among ordinary people in intelligence and personality depend equally on individual genetic variability and on differences in the environments that siblings experience within the same family, not differences in the neighborhood, school, and community environments. As of yet, there are no adequate theories to…

The growth model of intelligence; i.e. intelligence is the product of genetics plus environment (I.Q.=G+E), is discussed and questioned. If the growth model is discarded, formulating the problem of the development of intelligence in different ways and thinking of different possible technologies for changing intelligence can begin. The child…

Reviews the current theories concerning individual differences in cognitive functioning. While some argue that heredity places a genetic cap on intellectual development, others emphasize the dynamic interrelationship between cultural and environmental factors. Concludes that intelligence is more complex than the heredity advocates allow. (MJP)