26 THE MISMEASURE OF MAN
would want to know how Morton's conclusion about the inferiority
of cranial capacity in American Indians impacted the debates about
westward expansion—but would not generally think about sitting
down with Morton's tables of skull measurements and trying to fig-
ure out whether Morton had reported his data correctly.
I therefore found my special niche, for I could analyze the data
with some statistical expertise and attention to detail—and I do love
to study the historical origin of great themes that still surround us. I
could, in short, combine the scientist's skill with the historian's con-
cern. The Mismeasure of Man therefore focuses upon the analysis of
great data sets in the history of biological determinism. This book is
a chronicle of deep and instructive fallacies (not silly and superficial
errors) in the origin and defense of the theory of unitary, linearly
ranked, innate, and minimally alterable intelligence.
The Mismeasure of Man is therefore unabashedly "internalist" in
treating measured intelligence. I reanalyze the data of history's
great claims—in a way, I hope, more akin to forensic adventure (a
subject of general fascination) than of catalogues as dry as dust. We
will explore Morton's switch from mustard seed to lead shot in the
measurement of cranial capacity; Broca's meticulous statistics in the
odd light of his unconscious social prejudices; Goddard's altered
photographs of the imbecile line of Kallikaks in the New Jersey pine
barrens; Yerkes's supposed test of innate intelligence (but actual
index of familiarity with American culture) given to all army recruits
in World War I (and also, by yours truly, to classes of Harvard
undergraduates); Cyril Burt's great, crucial, and genuine error (not
his insignificant and later overt fraud) in the mathematical justifica-
tion of intelligence as a single factor.
Two famous and contradictory quotations capture the interest
and potential importance of this endeavor, this third aspect of my
frame for the mismeasure of man. God dwells in the details; so does
the devil.
Why revise The Mismeasure of Man after fifteen years?
I regard the critique of biological determinism as both timeless
and timely. The need for analysis is timeless because the errors of
biological determinism are so deep and insidious, and because the
argument appeals to the worst manifestations of our common na-