There is almost nothing more important to understand about people than intelligence. It can be measured more accurately than anything else in the social sciences. It differs tremendously and importantly between individuals. It is the single most important determinant of life success.
It's very existence, however, remains subject to substantive debate, most of it highly politicized. Dr. Richard Haier has recently written a major book on the topic,
The Neuroscience of Intelligence (http://amzn.to/2em55A9), summarized in the following manner:"This book introduces new and provocative neuroscience research that advances our understanding of intelligence and the brain.
Compelling evidence shows that genetics plays a more important role than environment as intelligence develops from childhood, and that intelligence test scores correspond strongly to specific features of the brain assessed with neuroimaging. In understandable language, Richard J. Haier explains cutting-edge techniques based on genetics, DNA, and imaging of brain connectivity and function.
He dispels common misconceptions, such as the belief that IQ tests are biased or meaningless, and debunks simple interventions alleged to increase intelligence. " We recently spent an hour and a half talking about such things.