Yes, personality differences can make a significant difference in performance on an IQ test, because even IQ tests involve test-taking skills. When faced with a challenging item such as found on the Raven’s progressive matrices, one person, will spend 10 or 15 seconds and then give up and move on to the next item. Another person will become more engaged, refusing to abandon the item in the belief that they can find the answer if they take the necessary time. Consequently, the person who abandons the item and moves to the next, may complete more items and achieve a higher score even though the two test-takers have the same level of intelligence. Optimal test-taking skills involve moving forward quickly, solving those items that are readily solvable, reaching the end of the test and then going back to re-try any items that proved difficult at first.
One brilliant actuarial scientist at the University of Toronto was famous for failing his actuarial examinations, because he would write a publishable treatise on the first question and then run out of time. It wasn’t an IQ test, but it reflects the mindset of some personalities.
Another observation I have made as I watch high-school students complete IQ or achievement tests, is the effect of motivation on the test outcome. Some students “run out of gas” after 20 minutes of effort and make only a half-hearted effort to complete all the items on an IQ test. When asked why they didn’t try harder, they may respond that it doesn’t affect their final marks in school. Another student who is highly motivated will look upon an IQ test as a vital measure on which they want to score high. Such a student stays on task with a single focus and obtains an IQ score commensurate with their ability.
Personality and motivation are vital in performance whether it’s academics, sports or IQ tests. Michael Jordan’s fierce competitive instincts and personal discipline were more important than his innate athleticism in his becoming an icon in basketball.
