Final answer:
The heritability of intelligence is between 50 and 80 percent, meaning that a significant portion of IQ differences can be attributed to genetics. Studies on twins have supported the idea of a genetic component to intelligence. However, environmental factors also play a role in intelligence.
Step-by-step explanation:
The heritability of intelligence is the degree to which IQ differences in a population can be attributed to genetic factors. Various studies have suggested different ranges for the heritability of intelligence, but the most commonly accepted range is between 50 and 80 percent. This means that 50 to 80 percent of the variation in intelligence among individuals in a population can be attributed to genetic factors.
For example, the Minnesota Study of Twins Reared Apart found that identical twins raised together and identical twins raised apart exhibit a higher correlation between their IQ scores than siblings or fraternal twins raised together. This supports the idea that there is a genetic component to intelligence.
However, it is important to note that environmental factors also play a role in intelligence. The study mentioned earlier also found that environmental influences provide both stability and change to trigger the manifestation of cognitive abilities.