Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Siblings more than 10 points apart??

My DD was tested when she was 4.8 yrs and found to be profoundly gifted with 150+ score on the WPPSI. She is currently in 2nd grade at a school for gifted children.
Her brother was just tested yesterday at age 4.5 and his score came back 18 points lower!!

My gut is telling me that there is something wrong here. His personality is different than hers, but we still see many similarities in learning.
The Dr. who gave the test was running 20 min. late, was rushing, didn't get his background information, etc. When she was done she sent him back to the lobby with me. THEN she called him back in because she forgot to give him part of the test!!!!

My question:
Has anyone had experiences with siblings with THAT much of a gap where there wasn't a learning issue?

Has anyone had a DC take the WPPSI-III where the results were completely inaccurate?

I'm trying not to be the "I think my kid is brilliant" mom, but something just doesn't seem right. I had always heard that siblings are normally within 10 points when they share the same parents and background.

I wouldn't worry too much about it. Here are my thoughts:

1. The WPPSI is sometimes described as not the best choice for HG+ children (although most often those statements are made with children closer to 6-7 years old).

2. IQ testing with younger children is a bit less accurate than with older ones.

3. I think that the tendency of children from the same family to have similar IQ scores has possibly been a bit overpromoted. I'm sure that children do cluster together that way, but it's not so uncommon for children to score more than 10 points apart either.

4. You're dealing with a lot of sources of variability: underlying variance in g; differences in test-taking skills; variability due to younger age (which may be the result of many factors including different academic exposure, even in the same household); different rapport with the tester; and differences in physical and emotional condition on test day. Kids are just different, and testing young children is less accurate than normal.

5. Even if rushing on the part of the tester may have been a factor, there's not much you can do about it now, except test in the future with a different person.

6. Your son's score likely meets whatever cutoff is used for your daughter's school. If so, what does it matter?

My sisters have to be at least 25 points lower than I am.
Possibly 30 to 35. They are just not that bright.

That's just life.

Note: I'm basing this on the difference of 500 points in SAT scores, which, given what I know about them seems right. Same with my father. He's not exactly the brightest bulb.

Same here, with my sister, though she is more of a traditional high achiever type than I am, with better organizational skills and ability to plow through boring material. My younger brother I'm uncertain about; he learns very quickly, but was never given much academic support, and is a bit of a jock and people-person.

that's just it, he doesn't with the score she said he tested with. You have to have an IQ of 140+ which this would put him shy of.

We are getting him tested with a different test and a different doctor in a few months. If she comes back with the same score then I'll feel better about the accuracy.

I just didn't feel like based on her comments we were talking about the same child.
But I was trying to find out if others had kids with this gap.

I mean, I can't even imagine how to handle two different schools and not making my DS feel like he goes to the "dumb" school even though he is still very very bright.

My two daughters have a difference of more than 20 points. I chalk it up to the fact that my highly gifted daughter was tested by a psychologist with the WISC who has 15+ years of experience working with gifted children. Whereas my older dd was tested by the school psychologist who tested her in a room right off the main hallway. DD was distracted to the point that some parts of the test were deemed invalid. I question the accuracy of this test. Also, she has dyslexia, possibly dyscalculia, and a weakness in receptive language that may have also affected her WISC results.

My kids do have a gap of a minimum of 15 points. But I can SEE that gap. It sounds like you did not have a good testing experience and a retest might not be unwarranted...

Yes, I would try to avoid that at all costs.

I read recently here that there is a GAI-like proxy for FSIQ on the WPPSI, but I can't find it by searching for some reason. I tried Google, but just couldn't pull it up.

My son tested at 5 with the SB-V and did well with it, even though he had before that had such a bad testing experience with the DAS-II that conclusive results couldn't be reported. The difference was a knowledgeable tester who took plenty of time to build up rapport with my son before the start of testing, vs. the school psychologist who understandably had experience mostly or exclusively in testing children on the other end of the bell curve, and for whom time was apparently not a luxury. His school-psych testing had him cowering under his chair, complaining of stomach pain, whereas he didn't have nearly the same amount of trouble with the outside tester.

My kids have FSIQs that are about 18 points apart. But their GAIs are only 8 points apart. The older one has dyslexia and ADHD. And remarkably, when you take the highest scores from the different times he's taken the WISC-IV, the older one's GAI is identical to the younger one's. I mean, I know you're not supposed to do that, but I think it's interesting, and it reinforces my belief (which is based on knowing them and having homeschooled both of them) that their underlying intelligence is the same.

My kids have siblings with IQs more than 18 points apart... but they aren't genetically related

Re different schools, it's pretty danged clear to my kids who the EG kid in our family is and who the uber-achieving kid with the HG+ IQ is in our family (and who the non-uber-achieving and MG-at-best IQ is). What we've always tried to do is simply to give each of our children all the opportunities we can to develop all their strengths, and with three kids with three different sets of gifts and three different personalities that at times has meant three different schools and means we spend a lot of time juggling schedules so that they can each participate in the schools and activities that they are interested in. At one point all three were in different schools - and it was great, because all three were in programs they enjoyed and were benefiting from.

In your situation, I'd do just what you're doing - get another test. If you don't *quite* have the scores to get into the school your dd is in, I'd appeal to the school - one point lower than the cutoff is certainly within the standard range of error on the test, and I'd use the sibling argument as reason to possibly suspect the test results (I have a friend who successfully argued this in our school district). Are there other criteria used for program entrance? Does your ds meet those? If it's just one test, one point below the line, that is an issue, I'd guess you could advocate his way into the program!

Best wishes,

polarbear