To maintain the mean score at 100 on IQ tests over the past 50 years, psychologists have adjusted by incorporating more verbal items and fewer performance items, ensuring the test reflects contemporary cognitive abilities. (option C)
Over the past 50 years, psychologists have maintained the mean score of 100 on IQ tests through a process called test renorming. They periodically update the tests to reflect changes in the population's overall performance.
This involves adjusting the difficulty of test items. Rather than making the test uniformly easier or harder, psychologists may choose to emphasize certain types of questions.
For instance, they might include more verbal items and reduce the number of performance items or vice versa. This meticulous process helps ensure the test accurately measures intelligence in the context of the current population, providing reliable and meaningful results. So option C is correct.
The complete question is:
Over the last 50 years or so, what have psychologists had to do in order to make sure the mean score on an IQ test remains at 100?
A. make the test easier
B. make the test harder
C. use more verbal items and fewer performance items
D. use more performance items and fewer verbal items