All of those social dynamics are explainable. Why are sprinters seldom White? Because fast people in Western cultures participate in the more-lucrative and high-status team sports instead. Why are boys dropping out? Well, African-American boys are punished more harshly for the same behavior, more likely to be diagnosed as learning-disabled and tracked out of regular classrooms, less likely to have their father at home due in large part to racist enforcement and prison terms. White boys aren't dropping out: they are under-performing because they don't have to work as hard to succeed as girls. Why are there mostly white men in the IT industry? I recommend this book: http://www.amazon.com/The-Computer-Boys-Take-Over/dp/0262050... It answers your question and it has nothing to do with who the best programmers are.
If you can't explain something, maybe you should do more research.
Grace Hopper and the Invention of the Information Age (2009): https://www.amazon.com/Invention-Information-Lemelson-Studie...
From airline reservations to Sonic the Hedgehog - a history of the software industry (2003): https://www.amazon.com/Airline-Reservations-Sonic-Hedgehog-C...