IQ is only approximately constant across successive examinations, with first-to-fifth IQ correlation of +0.82 and prediction error of 4 to 7 points¶
Claim · All claims
Evidence · 1 study · associationalr1·q2
Currency · newest study 1922 · not yet checked against its sources · not reviewed by a person
Subclaims¶
Reading the evidence codes
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q2 i? The correlation between first and fifth IQ is +0.82 for boys and girls over approximately 4 years; coefficients for larger groups range from +0.69 to +0.93, and IQ can be predicted with a PE of from 4 to 7 points. → Bird T. Baldwin 1922
Evidence¶
Bird T. Baldwin 1922¶
Bird T. Baldwin. (1922). The Relation Between Mental and Physical Growth. The Journal of Educational Psychology, Vol. XIII, No. 1. https://psycnet.apa.org/journals/edu/13/1/193
q2 · i? · associational · r1
Repeated Stanford-Binet (Stanford Revision) testing of 143 children begun in 1917, 42 with four and 36 with five consecutive examinations. The author reports "the coefficient between the first IQ and the fifth IQ is +0.82 for the boys and girls."
"the coefficient between the first IQ and the fifth IQ is +0.82 for the boys and girls, which indicates that they keep their relative positons after an interval of approximately 4 years."
Discussion¶
Related Claims¶
- IQs obtained by dividing mental by chronological age remain fairly constant up to the age of 14, which supports treating yearly increments of intelligence as equal absolute units up to about age 14. — related
- Yerkes-Bridges coefficients of intelligence of 1.20 or more are attained by very different percentages of children at successive ages (34.5% at ages 4-5 down to 0% at ages 16-17 and 18-on), so they do not represent the same degree of brightness at all ages. — related
- Growth measurements at age ten predict stature at sixteen within about 2.5 centimeters and IQ over the same period within 6.3 points — related
- Doctoral preliminary-examination grades and thesis ratings correlated about 0.6 with later success, while recommendation letters ranged from 0.01 to 0.70 — related
- The reviewer reports that Baldwin's repeated examinations show the IQ is fairly constant though subject to fluctuations, and that repeated examinations exhibit a definite practice effect — a broader claim this one bears on
- Early estimates place the IQ needed for successful first-year high school work between about 110 and 120 — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
iq-approximately-constant-prediction-error |
title |
IQ is only approximately constant across successive examinations, with first-to-fifth IQ correlation of +0.82 and prediction error of 4 to 7 points |
description |
IQ is only approximately constant across successive examinations, with first-to-fifth IQ correlation of +0.82 and prediction error of 4 to 7 points |
status |
review |
evidence_strength |
moderate |
newest_evidence |
1922 |
generated |
by process:wiki-ingest on 2026-10-24 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — bird-t-baldwin-1922 |
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