What is the 10,000-Hour Rule? What is the main claim of the chapters problematizing the concept of genius?

Malcolm Gladwell discusses this concept in the second chapter of Outliers. Even people who appear to have innate talent have to practice or work at their crafts for a long time in order to become proficient. It turns out that 10,000 hours is the amount you will need to put in to become an expert. According to neurologist Daniel Levitin, “It seems that it takes the brain this long to assimilate all that it needs to know to achieve true mastery.” Other attributes will no doubt factor into the person’s success as well.
The whole premise of Outliers is to debunk the stereotypical myth of the person who comes from nothing to claw his or her way up to the top of the field. The most successful people, even “geniuses,” are not just smart or talented. They don’t just put in the hours. They also often have cultural, historical, or linguistic advantages. Some of these are hidden and beneficial circumstances that they (and we) may not have even been aware of—until Gladwell brought the relevant research together for this book.