What does Gladwell in the book Outliers say about intelligence?
Outliers: The Story of Success by Malcolm Gladwell is in a sense intended as a refutation of the American mythos of the self-made man, who by extraordinary feats of will and intelligence triumphs over adversity to achieve some form of stunning success. Instead, Gladwell argues that environmental factors and sheer luck contribute to outstanding success.
For example, much of the technology boom of the past few decades has revitalized the notion of the extraordinary genius who succeeds as a technology entrepreneur. Although the outstandingly successful titans of the technology industry are certainly not stupid, their ideas depend for their success on a pre-existing infrastructure and some elements of being in the right place at the right time. For example, children born at certain times in the year can actually be eleven months older than other children in the same grade, giving them a major advantage in maturity. Although 11 months might not seem like a huge difference in students at university or adults, for a five- or six-year old that is almost a fifth of a lifetime.
Next, Gladwell advances what he calls the 10,000 hour rule. He argues that skill is not so much an innate factor, based on talent or intelligence, but rather the outcome of extended practice. To achieve extended practice, though, requires that a person be able to devote massive blacks of time to a specific activity. Thus a student from a poor family who needs to work while at school will have a more difficult time putting in 10,000 hours on schoolwork than a student fully supported by his or her family. A girl who can spend every afternoon practicing computer programming may end up more successful than one who spends every afternoon working a McDonald's rather than working on a computer. Thus intelligence is less important than the sort of environment which permits concentrated practice at a specific skill.