I would be inclined to disagree.
Here is a wikipedia article dealing with IQ and positive correlations with IQ, more specifically.
Edit: I notice you use the term "great" as a modifier for "indicator." I suppose depending upon the degree of greatness, I could be in agreement with you on that part. I do not, however, think it is "just neat to know, like blood type."
Although there is a positive correlation between a high IQ and success at work and school, one can plausibly argue that it is still not indicative of the fundamental qualities of a person's character.
Critics of the Bell Curve have raised the objection that the IQ test is manipulable and far too simple to be indicative of a person's true intelligence or other requisite merit for high performance as a student and an employee.
"Charles R. Tittle, Thomas Rotolo found that the more that written, IQ-like examinations are used as screening devices for occupational access, the stronger the relationship between IQ and income. Thus, rather than higher IQ leading to status attainment because it indicates skills needed in a modern society, IQ may reflect the same test-taking abilities used in artificial screening devices by which status groups protect their domains." (
The Bell Curve - Wikipedia, the free encyclopedia)
In other words, because of the inadequacy of the IQ tests, it is possible for people to attain high IQ tests by becoming good test takers rather than by displaying intelligence. Similarly to how people can attain degrees from universities by becoming 'good students' rather than displaying an aptitude for learning.
I do believe that you are correct to claim that there is a distinct positive correlation between having a high IQ and success in various aspects of life, however the view of the poster you disagreed with has merit. It could be argued that a person's blood type would be as highly correlated with success as IQ is today under certain social conditions. That is, if universities accepted applicants only with one particular blood type. This runs a parallel today to how many only accept students who are able to score highly on the GRE or ACT. Generally, a person's score on the GRE or ACT correlates highly to his IQ and so are the grades. Thus, if a person manages to succeed in one of those activities, he is far more likely to succeed in others than someone who hasn't managed to do so.
Simply put, the reason why people who score highly on IQ tests succeed than those who do not is not because they are far more capable of doing so, but because society offers them greater opportunities. This is not to say that people who are intelligent are not more any more likely to succeed than those who are not, but merely that IQ tests do not accurately indicate a person's level of intelligence.
To exemplify this point, consider the fact of the multitude of dull, yet industrious and ambitious students who manage to attain BAs and often MAs. Since they managed to pass many tests that are by far more intellectually demanding than any IQ test, its difficult to imagine that with sufficient dedication and perseverance, they won't be able to attain a high IQ test result. It is a striking fact about our educational system that a person's grades correlate highly to his ACT or GRE scores which also correlate highly to a person's IQ. However, since we do not have the temerity to assert that a person's grades accurately reflect his level of intelligence, we are not in the position to maintain that standardized IQ testing also does.
In recapitulation, we ought to consider the question regarding the cause of a person's success on IQ tests, academic standardized tests and grades. Since the correlation between the three is high, we have a compelling reason to believe that the three are connected and stem from the same root. Is the foundation of the person's success his intelligence, or is it an ability to successfully learn by route? In some cases, it is the former, in others the latter and in some a combination of both ensues. Clearly a clever person would have an easier time performing well in all three activities than one of average intelligence, yet this does not mean that the latter shall be incapable of success under any circumstances. The apparent simplicity of the IQ test leads me to suspect that one can indeed procure a high score by route learning.
