The Case Study that opened the chapter is motivated by research conducted in 1991 by Willerman, Schultz, Rutledge, and Bigler. Read about this study in the EESEE story "Brain Size and Intelligence," and use what you have learned in this chapter to answer the following questions.
1. How did the researchers measure brain size? Is this a valid measure of brain size? Is it reliable? Is it biased?
2. How did the researchers measure intelligence? Is this a valid measure of intelligence?
3. The researchers found some evidence that brain size and intelligence are related. However, the study described in Example 8 did not. Discuss the differences in the two studies.