ITHACA, N.Y., Dec. 3 (UPI) -- A new Cornell University study says the year in which one's IQ is measured can make major difference during one's life.
Such timing can affect the eligibility of children for special services, adults' Social Security benefits and recruits' suitability for certain military careers.
The study's lead author, Stephen Ceci, professor of human development, said IQ scores tend to rise 5 to 25 points in a single generation. This so-called "Flynn effect" is corrected by toughening the test every 15 to 20 years to reset the mean score to 100.
So, says Ceci, a score from a test taken at the end of one cycle can vary widely from a score derived from a test taken at the beginning of the next cycle, when the test is more difficult.
Such variations can mean death row prisoners might not be classified as mentally retarded in childhood because they took an older version of an IQ test. That, said Ceci, is the difference between being sentenced to life imprisonment versus lethal injection.
The study is published in the October issue of American Psychologist.
