Final answer:
It is incorrect to claim 50 percent heritability of intelligence means equal genetic and environmental influence because heritability refers to population variance, not individual causation. Heritability indicates how much of the variability in a trait within a population is due to genetic differences. Both genetics and the environment contribute to intelligence.
Step-by-step explanation:
It is incorrect to say that 50 percent heritability of intelligence means that the cause of your intelligence is 50 percent genetic and 50 percent environmental because heritability accounts for variations among people, not in specific individuals. Heritability estimates are about the degree of variation in a trait among individuals in a population that is due to genetic differences. Therefore, a 50 percent heritability does not imply a 50/50 causal contribution in an individual; rather, it means that half of the variation in intelligence across a population can be attributed to genetic differences.
Studies in the field reveal that intelligence is indeed influenced by both genetics and environment. Twin studies, like the Minnesota Study of Twins Reared Apart, illustrate that genetics plays a significant role. However, environmental factors like intellectual stimuli also have a substantial impact on intellectual development. The debate on nature versus nurture continues, acknowledging that both genetics and environment contribute to intelligence. The Range of Reaction theory further highlights the importance of environmental factors, indicating that while genetic potential is fixed, the actual intellectual outcome depends significantly on environmental stimulation.