Ordinarily. the human collective interacts with itself and learns to live with itself at the subliminal level. Certain groups of people have learned how to take advantage of that mechansim to manipulate human collective behavior in ways that are not beneficial to hmans or to the nature to which they are also connected, which also interacts subconsciously.
It is a misapplication of human intelligence and unjust to deceive the subconscious mind, but that's what these groups of people do. Just know that whatever you think or feel, that could be some mind pervert trying to control you. You may infer that I am not one of these, since they won't ever tell you they are doing it. This is good evidence because if you know about it, then you can resist them, and that ruins their control. At that point, they would have to resort to law and enforcement.
These controllers may try ot make you feel like a "rat" for telling someone about it, but you aren't because they are not part of you. A rat tells on people who are a part of its group, and you are not a part of their group. The most dangerous thing these people can do is enslave the minds of the people they parasitize, cuasing them to add their wills to an alien purpose. This is similar to a computer botnet, and these bots are known as "zombies."
You can even program these organically evolved parasitic techniques into digital media in order to automate these deceptions, literally blending these two domains of mind control!
With the collective power of these enslaved minds, the product of an information suppression cult, it is possible to force the will of an unwilling other, for example to make that other depressed.
In a civilization with euqal opportunity and where physical work equaled individual results, brain size would be the most predictive factor determining academic success. As it stands, that factor is only a weak predictor. (A lack of trust for the media or one's ambient human environment probably contributes more!) That means that group dynamics and privileged inertia account for the majority of variation in test scores.
Think about it! Why would humans have evolved big brains, to the poin that it is painful and dangerous to the woman to birth a human cranium unless brain size were an evolutionarily critical aspect of human intelligence? It could be functional regions? Well, the brain is exceptionally plastic, which means adaptive. Any functional region conferring increased intelligence would have reached fixation quickly, as intelligence is the most important human trait. It is possible, maybe, that there is a trade off between food availability versus metabolic rate, which may affect cognition. But that would have impaired white and Asian intelligence compared to African intellgence, since the agricultural revolution was followed by a period of nutritional decline and since the Holocene period adversely affected food supply for those populations.
Contrarily, it might be said that increased intelligence was necessary for those populations due to an increased ecological difficulty, and this may be slightly borne out in the 5% average brain size difference between Africans and the other two populations. But it is just as likely that increased population size, which lead to increased genetic diversity in the African population, required additional intelligence to confront social challenges.
In all likelihood, human intelligence is probably about the same for any individual from any race, with small idiosyncratic differences between geographically separated populations that could probably be removed through plastic adaptation.