IQ test scores what are they good for?
The majority of people have a rather limited notion of the practical significance of IQ tests. Many regard IQ tests only as an entertainment tool. However, statistical data reveal significant correlations between IQ test scores and many socially important factors like scholastic performance, learning ability and occupational performance.
Today, most scholars agree that all mental tests measure something called the general intelligence factor, which is a good indicator of one's innate mental abilities. Since IQ tests and other mental tests like aptitude tests and general-ability tests de facto measure the same thing, we can refer to the above simply as IQ tests. Having that in mind, we can now take a closer look at the importance of IQ tests.
IQ scores and school performance
Studies have shown that IQ tests are probably the best predictor of a child's success in school. This is in part because teachers’ grades are not always impartial. More importantly, IQ tests measure skills crucial to scholastic performance such as the ability to think logically and draw general conclusions from specific observations. Studies have also shown that children with higher scores on IQ tests exhibit greater learning ability and a deeper comprehension level of the studied material in school. This is especially true when learning is hierarchical, i.e. mastering previous steps in a certain process is a prerequisite for understanding later elements. The amount to which IQ test results are able to predict some other outcome, in this case success in school, is measured by the correlation coefficient between the two variables. The correlation coefficient can range from -1 to +1. Simply put, the closer the coefficient is to +1, the higher the correlation. Having said that, here are some interesting statistics about the correlation of IQ test results to some educational criteria:
Criterion |
Correlation |
Achievement in various elementary school grades |
.56 - .71 |
IQ in grade 4 predicts achievement in grade 6 |
.75 |
Reading readiness tests |
.84 |
Oral reading |
.62 |
Reading comprehension |
.68 |
Teachers’ estimates of pupils’ intelligence |
.60 - .80 |
Rank in high school graduating class |
.62 |
Freshman grades in college |
.44 |
Grade-point average in various colleges |
.30 - .70 |
Grade-point average in 48 colleges (median) |
.40 |
Grades in law school (median) |
.30 |
Highest level of education attained by age 40 |
.50 - .58 |
IQ scores and occupations
IQ scores are also fairly accurate in predicting one’s occupational performance. For example, high-level occupations show a correlation of .50 to .60 to IQ test scores for young men (ages 18 to 26) and of .70 for men over 40. In other words, the higher your IQ test scores, the greater the possibility of attaining a prestige occupation.
Other IQ score correlations
Finally, IQ test results show high correlations with some other factors of significant social importance like delinquency and criminal behavior, reaction time, honesty, achievement in extracurricular, nonacademic activities, musical aptitude, brain size and brain waves, and even nearsightedness.
In conclusion, IQ test scores are valuable predictive tools and an important part of our society.
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References:Jensen, Arthur R. Straight Talk About Mental Tests. New York: The Free Press, 1981. 29-37.