The topic is very dear to everybody's heart. But, in short it's just a single sentence hardworking people who have exploited their environment properly made it to the successful list. Having a high IQ or having great schooling and all can definitely add to that but does not guarantee success. The difference in every successful person against others of his time are pretty small but as they exploit their environment to their advantage well the difference keeps mounting and they stand out as outliers.
A great book but in the end it will make you feel smart people who understood and exploited their environment well could be successful. Their upbringing added a lot to that.
