SB IQ

%

SB#

Gau. 
SB S

Gau S 
LN S  SB Dev. IQ 
lnnorm IQ

160169

0.03

1

0.3 
1

0.3 
2.

154.5160.5? 
150156

150159

0.2

6

3 
7

3.3 
11

145.5153.7 
143149.4

140149

1.1

35

17 
42

20 
40

136144.7 
136142.7

130139

3.1

99

76 
141

96 
127

127135.2 
128135

120129

8.2

261

254 
402

350 
356 
118126 
119127

110119

18.1

576

484 
978

834 
834

108117 
110118

100109

23.5

748

758 
1,726

1,592 
1,592

98107 
100109

9099

23.0

732

2,458  
8089

14.5

461

2,993  
7079

5.6

178 
3,171


6069

2.0

64  3,235  
5059

0.4

13  3,248  
4049

0.2

6  3,254  
3039

0.03

1  3,255 
The first column in the
above table shows the StanfordBinet IQ range listed in Dr. Terman's table of
IQs found among the 3,184 children who were tested for the 1937 Revision of the
StanfordBinet IQ test.
The second column
gives the percentages of children falling within each 10point range of IQs.
In the third column, I've
multiplied the percentages listed in the second column by the number of children
(3,184) in the norming sample to estimate the number of children in each of Dr.
Terman's 10points IQ ranges.
In the fourth column are
the number of children that would be expected in each IQ range if IQs were
Gaussiandistributed.
The fifth column shows
the running sum of the numbers of children in each SB IQ range in the third
column. The fifth column represents the numbers of children at or above the IQs
in the third column (since IQ frequencies are usually specified in terms
of the number of children at or above a given IQ).
The sixth column presents
the same kind of cumulative distribution that would be expected if IQs were
Gaussiandistributed.
The seventh column
displays the same kind of cumulative distribution that would be expected if
these IQs were lnnormallydistributed.
The eighth column
exhibits deviationIQ ranges that would fit the StanfordBinet IQ frequency
data presented in column 5 (SB )
The ninth column shows
the deviationIQ ranges that would be predicted by a lnnormal distribution.
The SB deviation IQs derived from this data lie about midway
between the Gaussianpredicted IQs (which are equivalent to the SB IQs listed
in the first column), and the lnnormal IQs cited in the last column, this
normative data gives the children a median IQ slightly above 100, and it shows a
profile opposite to the distribution generated by the 192122 Terman Study,
where there were more children at the highest levels of IQ than are predicted by
a lnnormal distribution.
Of course, the numbers are sufficiently small at IQs above
150 that random sampling fluctuations could tilt the results either way. (For
example, it would be easy to find two children with ratio IQs above 160 in this
size sample.)