In his book “On Intelligence,” Jeff Hawkins says that intelligence is the ability to detect and predict patterns. I would go a step further and say that the signature of human intelligence is the ability to then create new patterns. If we look to what it is that IQ tests test for, it is pattern recognition. The more complex the patterns are that one can recognize, the more intelligent a person is said to be. Of course, there are many kinds of patterns, and some people are better at picking up some kinds patterns than they are at others. Thus there could be social intelligence, emotional intelligence, psychological intelligence, artistic intelligence, literary intelligence, memory-intelligence, mathematical intelligence, etc. Some patterns, like those in math, are extremely simple patterns — so simple that math is difficult for many people.
So we see a variety of kinds of intelligence. We should also then expect that, with the way we measure IQ, we should see differences in IQ based on the complexity of a society one finds oneself in. People in more complex societies, cultures, and sub-cultures would then test as having higher IQs than do those in less complex societies, precisely because those in more complex societies would be more likely to encounter and have to recognize more complex patterns. Complexity in a society (or in a person’s mind) is something that emerges over time. Some places, due to any number of factors, have more complex societies than others. When an environment changes, a society can and oftentimes will react to become more complex. This helps to make sense of the fact that IQ has steadily gone up in Western countries throughout the 20th century (it doesn’t appear to be the case only because by definition 100 is average, meaning they have had to modify the tests). Obviously, evolution could not be working quite that fast, to make people at the end of the 20th century smarter than those at the beginning. However, I think we can all recognize that Western culture and society have gotten more complex over that same period. People living in the more complex societies, being exposed to more complex patterns, would naturally be able to detect the more complex patterns associated with high IQ. This also makes sense of the fact that IQ can and does oftentimes go up as a person gets older. Some children can see complex patterns right away and easily. Others learn to do so.
Is there a genetic component to IQ? Unquestionably. But with 1/3 of our genes being expressed exclusively in the brain, good luck figuring out what combinations make for high intelligence. Also, the massive shifts and migrations of people throughout history and pre-history, along with the bottlenecking that occurred several tens of thousands of years ago to make us almost genetically identical, makes any racial component to IQ so unlikely as to be almost laughable. Intelligence comes about through the interaction of genes and environment, and the more complex the environment is, the higher the IQ of the people in that environment. As noted, social-cultural-environmental differences are accidents of geography as much as anything, as Jared Diamond observed in “Guns, Germs, and Steel.” As the world becomes more complex, other cultures around the world will respond to that complexity — sometimes by lashing out, sometimes by becoming more complex themselves. But we have to recognize that this is where the differences lie: in our psychosocial complexity. It is that component to IQ that is variable among groups, not genes. The world we live in, and how complex we think the world is that we live in, makes a difference. Individual differences, rather than group differences, may be another matter, as different individuals may be better or worse at detecting patterns, or certain kinds of patterns. And there is certainly a difference in ability to create new patterns. Artists, poets, and musicians aren’t all that common, after all. But my guess is that they are also less common than they could be.