Academics have for over 100 years measured intelligence using IQ tests, but the Flynn Effect they’ve found doesn’t necessarily mean we are more intelligent than our grandparents. We may just be better at taking tests.
Aptitude tests are one way of measuring intelligence, but scholars note that most aptitude tests are biased from the writer’s point of view. Asimov one wrote that he believed himself smarter than his car mechanic, but if the mechanic had devised a test of intelligence Asimov would almost surely have failed.
For years, many researchers associated skull size with high IQ. But science has found that intelligence isn’t related to brain size or structure, but instead to how efficiently information travels through the brain. The frontal and parental lobes play the most important role in IQ; it’s not a coincidence that these areas also control attention, memory and language. But intelligence is scattered throughout the brain (no region is wholly responsible). Perhaps this explains why some people have higher levels of artistic talent, math skill or musical ability. Since no single structure is responsible for general IQ, different types of brain designs may produce different types of intelligence.
Understanding the path intelligence takes throughout the brain can boost IQ. It can also help treat people who are intellectually or developmentally disabled. Dissecting how we learn can be an important aid for children in schools. But even an IQ test does not account for all types of brainpower. As Einstein said, the true sign of intelligence isn’t knowledge but imagination.