One concept that I found interesting about intelligence was the debate regarding the use of SATs and college aptitude tests to predict how students would perform in the future. We all had to take at least one of these tests, but I still wonder what they're even measuring. I've heard before that the SAT, ACT, and GRE were not designed to predict an individual's GPA. As I learned from the excerpt on Lilienfeld p. 331, the crucial piece that's overlooked when people dismiss these tests as useless is this: colleges don't admit the lowest scorers, so the intelligence "playing field" is somewhat evened in college admissions requirements. This article on the ABC News website has a great soccer "SAT" analogy that helped me think about this concept.
Basically, the people who scored low on tests in high school generally don't attend college, so some of the previously "average" students will struggle and become those students with the lowest GPAs. Conversely, some of the "average" people may get motivated and work hard to obtain a great GPA; some lazy, brilliant students may slack in their newfound freedom and start to fail in class. While these intelligence tests can't perfectly predict how students will perform in college, some of the variability in first-year GPA can be explained using the soccer analogy. It's important to remember that the SAT is a rough estimation/comparison tool, not the final word in admissions; so, study hard but relax about your upcoming GRE!