Pergamon
P~NMI.
I&W/
Dtff Vol. 19. No.
I. pp. 113-l 15. I995
Copyright P 1995 Elsrwer Scmcr
Lrd
Pnnted I” Cirear Bmam. All rights re\emed
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Brain size and intelligence:
erratum, addendum,
and correction
Vincent
Egan.‘.*
John C. Wickett’
and Philip A. Vernon’
‘Depnrtment
of Psyhology
/Clinic01 Section). Unir~ersi~ of Leicester.
Leicester
LEI 7RH. England
and ‘Deportment
of Pswholog~.
Uni\~ersit~ of Western Ontario.
London, Ontario.
Canada N6A SC-1
(Receiwd
3 October
1991)
Summary-The
current papercorrects
some previously
published results (Egan. Chiswick.
Santosh, Naidu.
Rimmington
Br Best. Persona/it?
tend IndirYdunl
Differences.
17, 357-367.
1994). and suggests that the
mnge-corrected
correlation
between total brain volume and Full-Scale
IQ. controlling
for height and weight.
is 0.18 not 0.66. This result replicates correlations
of similar sizes found by researchers
from four different
research teams. The high correlation
between CSF volume and IQ measures
in this study
is discussed
in
reference
to the method of estimating CSF volume.
It is suggested
that an automated method may have
provided an indirect measure of brain surface area. Finally.
by simulatin, 0 the range of possible partial
correlations
brtueen
brain volume and intelligence
controlling
for height and weight,
it is argued that the
correlation
betvvecn brain volume and measures of IQ is only modestly affected by correction
for body size.
As such, brain volume/IQ
coefficients
should only be corrected
for body size if data from the specific study
warrants such a procedure.
ISTRODUCTION
A number of recent studies have reported significant
and substantial
positive correlations
between brain volume (as measured
by magnetic
resonance imaging) and measures of intelligence
[as measured by standard psychometric
instruments
(Willerman,
Schultz, Rutledge & Biplrr.
1991: Andreascn. Flaum, Swayze
II, O’Leary,
Aliger. Cohen, Erhardt & Yuh, 1993; Raz. To