Final answer:
The 30% figure mentioned in the question represents the genetic contribution to SAT score variability or heritability. Lurking variables challenge the notion that genetics alone determine SAT scores, emphasizing the role of environmental and social factors in intellectual development and test performance.
Step-by-step explanation:
The 30% figure represents Professor Mackenzie's assessment of the genetic contribution to SAT score variability. This is an estimate of how much genes influence the differences in SAT scores among a group of high school students. It falls under the concept of heritability, which is the proportion of variation in a trait that can be attributed to genetic differences among individuals within a population.
Lurking variables, such as educational background, motivation, gender biases, and cultural factors could offer alternative explanations for SAT score differences, challenging the conclusion that genetics are the sole factor. These lurking variables highlight the complexities of attributing performance on standardized tests like the SAT solely to genetics, as they could also be greatly influenced by a combination of environmental factors, educational policies, and social dynamics.
It is important to consider that while genetics can provide a basis for intellectual potential, the actual expression of abilities is also dependent on the environmental stimulation one experiences, especially during critical developmental periods like childhood. The interaction between one's genetic predisposition and environmental factors is what ultimately shapes individual performance and aptitudes.