The influence of the e4 allele of the apolipoprotein E gene
on childhood IQ, nonverbal reasoning in old age, and
lifetime cognitive change
Ian J. Dearya,*, Lawrence J. Whalleyb, David St. Clairb, Gerome Breenb,
Steve Leaperb, Helen Lemmonb, Caroline Haywardc, John M. Starrd
aDepartment of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, Scotland, UK
bDepartment of Mental Health, University of Aberdeen, Aberdeen, UK
cMedical Research Council Medical Genetics Unit, Edinburgh, UK
dDepartment of Geriatric Medicine, University of Edinburgh, Edinburgh, UK
Received 28 June 2001; received in revised form 4 March 2002; accepted 7 March 2002
We examined the influence of APOE e4 allele status on three cognitive outcomes in the same
sample of 173 people: (i) IQ (Moray House Test) at age 11 years, (ii) IQ (Raven’s Standard Progressive
Matrices) at age 77 years, and (iii) change in IQ between age 11 and 77. All participants took part in
the Scottish Mental Survey of 1932 and were followed-up in 1997–1998. There was no significant
main effect of gene status on IQ in youth or old age, nor in cognitive change across the lifespan. Sex
had no effect on the three cognitive outcome variables and did not interact with APOE e4 allele status.
D 2003 Elsevier Science Inc. All rights reserved.
Keywords: APOE; Intelligence; Ageing; Genetics; Dementia; Cognition
Individual differences in psychometric intelligence are partly heritable (Bouchard, 1998).
The heritability is probably higher in old age than in childhood (McClearn et al., 1997;
Plomin, DeFries, McClean, & McGuffin, 2001). Therefore, it is possible that different genes
0160-2896/03/$ – see front matter D 2003 Elsevier Science Inc. All rights reserved.
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* Corresponding author. Tel.: +44-131-650-3452; fax: +44-131-651-1771.
E-mail address: firstname.lastname@example.org (I.J. Deary).
Intelligence 31 (2003) 85–92
contribute to intelligence differences at different stages in human life. Heritability estimates
are not inf