Why do white people think they know everything?
Though research on the subject is sparse, I will try to answer this with an evaluation of the best scientific hypotheses available as I’ve found in scholarly journals after completing an in-depth five-minute Google Scholar search.
After evolving from pigs, white people spent centuries grooming each other. Over the years, this grooming process became more and more specialized. At first, white people chewed on each other to promote their dermatological health and to encourage their expansion across the continents, as it is currently believed that white people necking may result in reproduction. Eventually, this grooming became far less physical and more cultural. In the 1800s, post-secondary education became more accessible amongst white people, mostly due to the industrial revolution and the increased wages and living incomes this provided for rich people. In time, even complete idiots were able to find good jobs after receiving a degree. White people were, by and large, the only people able to pursue this level of education.
As the popularity of university and post-secondary institutions grew, the culture of the White Person began to value the knowledge gained in these institutions over knowledge gained by any other means. Because people of color still had limited access to these institutions, they weren’t privy to the information taught there and, with so few people of color becoming distinguished in the world of academia, the White Person began to think they were the only ones with any knowledge.
This belief continues to this day, even as people of colour continuously redefine knowledge and where it comes from.
I hope that helps!