*Can
the Flynn Effect Dwindle As the IQ Rises?*

All IQs in the following discussion are based upon a
standard deviation of 16.

In arguing that the Flynn Effect cannot be dependent upon IQ,
I assumed that the Flynn Effect acts uniformly over all age groups. But
supposing it isn't. Suppose that someone who today has a deviation IQ of 143
(present-day ratio IQ of 150) actually only has a present-day ratio IQ of 125
(present-day mental age of 20). And someone today with a deviation IQ of about
174 (equivalent ratio IQ of 200) really only has a present-day ratio IQ of 150
(present-day mental age of 24). In other words, suppose that the distribution
curve for the upper half of the year-2002 distribution for intelligence is only
half as wide as it was in 1916, with a standard deviation of 8 instead of 16.
After all, if we measure adult IQ's, and since 1986, even children's IQs, only
with deviation IQs (frequencies of occurrence,) we have no idea what their
actual levels of capability are.

The average present-day young adult (present-day IQ = 100,
present-day mental age = 16)) will score a 1916 IQ of 133 (1916 mental age =
21.33) on the 1916 edition of the Stanford Binet IQ test, or on a comparable IQ
test of that vintage.

Today's citizen with a deviation IQ of 143 (which would have
corresponded in 1916 to a ratio IQ of 150, but which would only correspond to a
ratio IQ of 125 today, with a present-day mental age of 20) would have a 1916
mental age of 4/3 X 20 = 26.67, and a 1916 ratio IQ of 26.67/16 = 166.67.

Today's citizen with a deviation IQ of 174, standard
deviation = 16, (equivalent in
1916 to a ratio IQ of 200, but equivalent to a ratio IQ of only 150 today, with
a present-day mental age of 24) would have a 1916 mental age of 4/3 X 24 = 32,
and a 1916 ratio IQ of 200 (1916 deviation IQ of 174, standard deviation = 16).

This would give us a situation in which past geniuses with
ratio IQs of 200 would be as bright as today's phenomenally gifted adults with
ratio IQ's of 200 (deviation IQs of 174, standard deviation = 16). At the same time, it would let us
explain how the average IQ of today's average young adult is 133 on a 1916-era
IQ test.

But I don't think it holds water. Here's why.

In 1988, Dr. Miraca Gross identified 15 children from South
Australia, Victoria and the Australian Capital Territory with ratio IQs of 160
or higher on the Third Revision (1973) of the Stanford Binet Intelligence Test.
Three of these children obtained an IQ score of 200 or above. One of these,
Christopher Otway, hit the ceiling of the test, with a mental age of 22 at the
chronological age of 11. A few months later, "At the age of 11 years, 4
months he achieved the phenomenal score of 710 on the *Scholastic Aptitude
Test-Mathematics (SAT-M)* (SAT), and 580 on the *Scholastic Aptitude
Test-Verbal (SAT-V)*. To extend the testing further, the psychologist
administered the *Wechsler Adult Intelligence Scale (WAIS-R)*. Here
Christopher performed at the absolute maximum on abstract reasoning and
arithmetic, placing him in the 'very superior' range even compared to
adults."

The Third Revision of the Stanford Binet Intelligence Test
would now be 29 years out of date, leading to a Flynn Effect of about 9 points.
Since we're dealing with an IQ at the 200 level, and since I think that the
magnitude of the Flynn Effect is directly proportional to the IQ (for
above-average IQs), I'm going to assume that Chris' 1988 IQ of 200 can be
de-rated by 18 points because of the Flynn Effect. On the other hand, since he
bumped his head against the ceiling of the test, I'm going to assume that his
actual IQ was somewhat higher than 200. In fact, I'm going to assume that it was
about 218, which will allow us to retain a mental age of 22 as measured by
today's standards. His IQ in 1988 would then have been 218 relative to other
11-year-olds. His adult IQ on today's scale would be 200 because of the
Flynn Effect. But we have assumed above that a present-day IQ of 200 corresponds
to a present-day mental age of only 24, so Chris' mental age at 16 and beyond
would be only 24. Now let's see. When he was 11, he had a mental age of 22. At
16, his mental age was 24. Consequently, he would have added only 2 years to his
mental age between the chronological ages of 11 and 16 In other words, his
mental age was increasing by 2 years per year up to the age of 11, and then
slowed down to an average of 0.4 years per year between 11 and 16.

I don't believe that happened. Do you?

__To Summarize:__

As recently as 1988, ratio IQ's were alive and well for
children with IQs above 200 up to at least the age of 11. Presumably Dr. Linda
Silverman's Gifted Development Center has measured many more of these
phenomenally high IQs that are based upon mental ages, as provided by the Third
(1973) Revision of the Stanford Binet Intelligence Test.

__Tests That Could Test
This Hypothesis:__

The Slossen Intelligence Test (S-FRIT) (1993) extends upward
to a mental age of 27.

Form S of the California Test of Mental Maturity ranges
upward to a ceiling mental age of 32. (American Mensa has bought the rights to
this test, and has assigned a deviation IQ ceiling of 168 to it . . . a number
that seems generous considering the 45 years that have elapsed since Form S was
published.) It's ceiling would have to be de-rated by about 4 years of mental
age to compensate for the Flynn Effect, giving it a mental age of ceiling of
about 28 today.

If we can find a significant number of subjects who score
higher than a mental age of 24 on either of these tests, then we will have
succeeded in falsifying the hypothesis that the above-average adult intelligence
distribution has shrunk to half its 1916 width.

We can begin with me. I had a mental age of 29 years on the
CTMM when I took it in 1979, and of 30 years, 8 months when I took it in 1999
(before correcting for the Flynn effect). The first time I took the test,
in 1999, I made 3 errors each on two of the 7 subtests (*Similarities* and *Verbal
Concepts*) of the test, with perfect scores on the other 5 subtests. (It
would seem that I was limited by the ceiling of the test.) The second time I
took the test, in 1999, I made perfect scores on 6 of the 7 subtests, with the
same 3 errors on the Similarities subtest. Correcting these numbers for 45 years
of Flynn Effect yields 25.55 years of mental age for the first try in 1979, and
27 years of mental age for the second attempt in 1999. These mental ages,
after correcting for 45 years of Flynn Effect, correspond to present-day
ratio IQ's of 159.7 and 167.5. If our hypothesis about the upper half of the IQ
distribution having shrunk to half its width were correct, my present-day mental
ages of 25.55 and 27 would translate to deviation IQ scores of 184 (1 in
13,000,000) and 192 (1 in 225,000,000), respectively. And this on a test on
which I got perfect scores on first 5, and then 6 out of the 7 subtests! Sorry.
I like it, but it doesn't fit..

The idea that the Flynn Effect diminishes to the vanishing
point as IQs rise would allow the great minds of the past to possess IQs as high
as those of the present day. Unfortunately, I don't think that's the case. I
think the Flynn Effect is proportional to both time and IQ. However, it should
be very easy to test this hypothesis simply by giving present-day subjects with
known present-day IQs old tests, and looking at their resulting IQ distributions
on those old tests.