IQ matters: All things equal, some students will learn more than others

Some people are smarter than others, writes psychologist Russell T. Warne in Quillette. Providing excellent curricula and experienced teachers will not narrow achievement gaps. Weaker students learn more in good schools, but stronger students will learn a lot more, so individual differences in achievement will widen.

In developed countries, "only about ten percent of differences in learning outcomes are related to school- and classroom-level characteristics," he writes. Most are related to intelligence and -- because most children are raised by their biological parents -- to family characteristics influenced by genetics.

Many U.S. educators are in denial about the importance of intelligence, his research shows. In a survey of 200 teachers, more than "85 percent believed that it was too simplistic to measure someone’s intelligence with just one score, like an IQ," Warne writes. Almost 85 percent endorsed the discredited theory of "multiple intelligences," and almost 40 percent "thought that 'street smarts' were more important for life success than intelligence." These "beliefs are completely incorrect," he writes. "In contrast, only a third thought that students who perform better on intelligence tests would also perform better in school." That one is correct.

Warne thinks bright students should move more quickly through school: Up to a quarter of high-school students could start college a year early, and five to 10 percent could skip two years, research shows. "There is no evidence that grade skipping creates any harms — academically, socially, or otherwise — for children."

Teachers are being asked to customize lessons for children who are way ahead and way behind, but placed in the same classroom. That doesn't work for anyone, he believes. Some students need more than 13 years -- and a lot of extra help -- to complete the K-12 curriculum, he writes. "Almost ten percent of 12th graders have lower reading achievement than the average 4th grader."

Giving all students a chance to attend orderly schools with high-quality curriculum and well-trained teachers is a worthy goal, even if it doesn't equalize outcomes or close achievement gaps. We don't know who's intelligent until we give them a chance to learn. But we shouldn't pretend that schools can do everything.