In this part, we meet the third great controversy, the “intelligence war”: Does each of us have an inborn general mental capacity (intelligence)? Can we quantify this capacity as a meaningful number? And can we measure intelligence without bias?

School boards, courts, and scientists debate the use and fairness of tests that assess people’s mental abilities and assign them a score. Is intelligence testing a constructive way to guide people toward suitable opportunities? Or is it a potent, discriminatory weapon camouflaged as science? First, some basic questions:

• What is intelligence?

• How can we best assess intelligence?

• How does intelligence change over time and vary among individuals?

• How do heredity and experience together weave the intelligence fabric?

• What intelligence test score similarities and differences exist among groups, and what accounts for those differences? Should we use such differences to track the abilities of students? To admit them to colleges or universities? To hire them?

This part offers answers, by identifying a variety of mental gifts and concluding that the recipe for high achievement blends talent and grit.

Myers' Psychology