Discrepancy in IQ scores
By Inderbir Kaur Sandhu, Ph.D
My daughter has had an IQ test at 5 and came out in the 96th
percentile she then had an IQ TEST at 8.5 yrs and her IQ had
fallen to the 84 percentile. She has been diagnosed with
dyslexia and auditory processing disorder. Is it possible to
have such a huge variance in the IQ TEST results?
She was tested with WPPSI-R and WISC -IV I am concerned she
has add as her processing speed is very low at 53
percentile. She was sick when the test was administered -
she was recovering from pneumonia. She is performing really
poorly at school and it not even at an average level. She
has suffered from chronic tonsillitis and anemia for a good
12 months too. Are you able to shed any light on this!!
A: At a glance, it does appear
to be a rather significant drop but as one notes the
circumstances, for instance, 3.5 year gap, her learning
difficulties which may be more pronounced, and her condition
when the test was administered indeed justify the results.
Processing speed generally refers to the varying speed with
which individuals are able to perform cognitive activities
such as the recognition of simple stimuli. Higher speed in
cognitive processing usually allows more information to be
acquired in a shorter time span enabling the individual to
absorb and master materials of higher levels. Above average
individuals usually have high processing speed, thus
enabling them to reach developmental milestones ahead of
their age mates. In layman's terms, the brain is working
faster which is viewed as superior intelligence, hence the
difference in human intelligence.
Having said that, there is more to intelligence than speed
of processing, which is the reason most IQ test use a
combination of factors to assess intellectual skills.
According to the WISC, processing speed measures children's
abilities to focus attention and quickly scan, discriminate
between, and sequentially order visual information. It
requires persistence and planning ability, but is sensitive
to motivation, difficulty working under a time pressure, and
motor coordination too. Cultural factors seem to have little
impact on it. It is related to reading performance and
development too. It is related to Working Memory in that
increased processing speed can decrease the load placed on
working memory, while decreased processing speed can impair
the effectiveness of working memory.
Due to your daughter's medical condition, these may have
been interfered with. Perhaps you need to see a pediatrician
to help with her medical issues and that may be the
underlying concern that needs immediate attention. You did
mention ADD. Apparently, lower processing speed scores could
indicate such concerns. There are children with ADHD who
have IQ scores in the gifted range, yet rather low
processing speed. This is definitely a concern and I'm
afraid I can only advise you to seek medical opinion, and
once diagnosed with any medical related problem; perhaps an
intervention strategy can be planned to help her in school.
I believe she needs an individualized program in school.
Hope the above helped shed some light on your concerns. Best