Two stories. First, I have a close relative whose life has not worked out well. You could talk about character or you could talk about mental stability or you could talk about social relationships in trying to explain her failure to live up to the potential everyone saw in her in her youth. Using these tools, maybe you could explain her unhappiness and her poverty somehow, but it still wouldn't improve her circumstances or make her happy. But, here's the thing: she is inordinately proud of being a member of MENSA. She has the official IQ stamp of approval. She is one of the smart ones, and she wants you to know it. She hasn't achieved anything in her life, but she's brilliant. So, what does IQ score mean in her case?
Second story. When I was working on my doctorate in edjumacation, the subject of IQ came up several times. One of the professors said that his wife had subjected him to every IQ test there was when she was working on her doctorate in school psychology. She had to administer so many IQ tests of so many kinds in order to earn her degree, you see, and he was a handy guinea pig. We started talking about IQ tests, what they measure and what they don't. I said that I refused to ever take an IQ test again. Why would I refuse? they asked. So I told them this story.
When I was in 7th Grade, I was a typical 12-year-old boy in most ways. Fidgety at times, not always diligent. I was also spookily bright. Not that I thought of myself as all that exceptional, but others noted it. Anyway, because I was so obviously bright, teachers kept trying to get me to "work up to my potential," which I saw as a straitjacket. They wanted me to do more meaningless worksheets, or to behave in what they saw as a more mature fashion, or to like schooly stuff more. I would, instead, do the assigned work as fast as I could in order to gain extra time to read and think for myself (and act up, no doubt). I saw that time as my own; the teachers saw it as extra time for them to make me do things. I felt this was grossly unfair.
Anyway, my 7th Grade English teacher asked for a conference with my mother. She dutifully trooped into the school and heard him out. As she related the details of the meeting to me later, the teacher gave a long list of complaints about my not working up to my ability, blah blah blah. I was capable of so much more, he said. He had a file in his hands. The results of my latest IQ test were in it. He told my mother my score. Then he said, kind of reflectively, "Mine's not that high." And then went on to say that with that level of IQ, I ought to be, and so forth. After she got home, I asked Mother what it was all about. "He's jealous of your IQ," she said. There was nothing wrong with me. She advised me to grind out the assigned work and bug the teacher less.
I shrugged it off at the time, but in the years since I had come to see how IQ scores are often used improperly. Some people are proud of their score but think that that number somehow gives them value in excess of their achievements. Other people are embarrassed about their score and think that it detracts from the value of their achievements. And, too often, educators feed both the unrealistic pride and the unrealistic shame. They use IQ, as they use other measurements, to sort children into different groups with different expectations. And then they treat them differently. They give more opportunities -- and more positive attention -- to some kids than to others, because they think this number means something special.
Now, speaking as someone who today would be called a "gifted and talented" kid, I have always said that the problem with most "gifted and talented" programs in schools is that they are not taught by gifted and talented people. They are taught, in large part, by the same gradgrinds who went into teaching because they liked school.* They want the bright kids to jump at the chance to do more silly worksheets, to perform dull tasks faster, and to eagerly reflect the value the teachers see in school. But truly gifted and talented people often show impatience with makework tasks, they solve problems in unusual ways not listed in the answer section of the teacher's book, and they often want to follow their own interests and not the teacher's.
In any case, having once been pigeonholed and hassled for my IQ score by someone in authority, I decided that I didn't need a number to validate my intelligence. Nor would I pin numbers on other people and decide whether they were worth paying attention to on the basis of their scores. And I would never, ever take an IQ test again, not even for my own curiosity.
*Education majors, as a group, have the lowest GPA of any college major -- which includes their grades from softball education courses. This, of course, only describes the group as a group. It should not be used to demean truly bright teachers who both know their stuff and know how to get kids to learn it. I know many great teachers. I also, alas! have known too many who could best be described as a geologist's footlocker.