What do your textbook authors conclude about the nature of human variation?

What do your textbook authors conclude about the nature of human variation? The traditional concept of race still is used by many medical professionals even though it generally is not considered a valid biological construction. Why is it still used in medicine? A legitimate scientifi c pursuit is the exploration of possible intellectual differences between groups. Explain why IQ and other standardized tests are not good measures of the comparative intelligence of different populations.