Final answer:
Heritability is the concept used to describe the proportion of observed differences in IQ among individuals that can be attributed to genetics. In a fully controlled environment, differences in IQ would likely signify a high heritability factor. Studies like the Minnesota Study of Twins Reared Apart support the genetic influence, but the environment still plays a role in intelligence.
Step-by-step explanation:
In the scenario where four boys are raised in a 100% controlled environment, yet exhibit different IQ levels, heritability is a key concept in explaining these differences. Heritability is the proportion of variation among individuals in a population that is due to genetic differences. If the environment is completely controlled and differences in intelligence still persist, heritability would potentially be high, where genetics play a significant role in the variation of IQ among the boys. Moreover, the concept of Range of Reaction fits this scenario, which posits that while each individual's genetic potential is fixed, the actual expression of traits, such as intelligence, depends to a significant extent on environmental factors. Therefore, in a controlled environment, the remaining differences in IQ scores would largely be attributed to genetic variation.
Studies, like the Minnesota Study of Twins Reared Apart, have shown a strong correlation between IQ scores of identical twins whether raised together or apart, suggesting a genetic component to intelligence. Additional insights from twin studies and longitudinal research indicate that behaviors and environmental stimuli have an impact on the development of intelligence, but the genetic component should not be ignored, with many traits exhibiting significant heritability ratios. This reinforces the idea that high intelligence comes from a combination of genetic factors and environmental influences.