Awhile back I learned of a really interesting statistic in Malcolm Gladwell's book Outliers.
In some standardized tests, test administrators like to ask students survey questions before the test so they can try and correlate test performance to other social factors. These questions are pretty normal, things about your social life, friends, and family. However, this survey is so long and tedious that many students just give up and don't even complete the survey before taking the test.
What several researchers found was that there is a strong correlation between percent of the survey completed and performance on the test. Students that complete a higher percentage of the survey perform better on the test. Note that it's not how they answered the questions on the survey, simply the fact that bothered to complete to the survey.
The suggestion is that patience, diligence, and work ethic are actually more important than smarts. If you can stomach through this tedious survey, you've probably stomached through a lot of homework assignments to be able to learn the material well.
Not so long ago, I was on a committee to review a contract for a procurement. While reviewing the bids, I noticed that there were bids that were horrifically bad. At the same time I noticed the bad bids were much shorter in length than the better bids. In fact, by the time the committee was done with the selection process, the ranked order of the bids was strongly correlated to the thickness of the printed bids. My recollection is that if only two bids had been flipped in their ranking, the correlation between thickness of printed bids & rank would have been perfect.
It got me thinking, the correlation was similar to the correlation with the standardized tests. The companies that put in way more effort and time into their bids, probably cared about their bid a lot more. At the end of the day, the fact that they cared about the bid a lot more, probably meant they wanted to win the contract a lot more, and meant they would care about fulfilling the contract a lot more.