2^ (^2) THE MISMEASURE OF MAN
TEST FINISHED NOT FINISHED
1 2 3 4 5 6 7
44
21
45
12
18
49
40
9
32
8
41
35
4
13
some had never taken a test before or even held a pencil. Many did
not understand the instructions and were completely befuddled.
Those who did comprehend could complete only a small part of
most tests in the allotted time. Meanwhile, if anxiety and confusion
had not already reached levels sufficiently high to invalidate the
results, the orderlies continually marched about, pointing to indi-
vidual recruits and ordering them to hurry in voices loud enough,
as specifically mandated, to convey the message generally. Add to
this the blatant cultural biases of test 6, and the more subtle biases
directed against those who could not write numbers or who had
little experience in writing anything at all, and what do you have
but a shambles.
The proof of inadequacy lies in the summary statistics, though
Yerkes and Boring chose to interpret them differently. The
monograph presents frequency distributions for scores on each
part separately. Since Yerkes believed that innate intelligence was
normally distributed (the "standard" pattern with a single mode at
some middle score and symmetrically decreasing frequencies away
from the mode in both directions), he expected that scores for each
test would be normally distributed as well. But only two of the tests,
maze running and picture completion (l and 6), yielded a distri-
bution even close to normal. (These are also the tests that my own
students found easiest and completed in highest proportion.) All
the other tests yielded a bimodal distribution, with one peak at a
middle value and another squarely at the minimum value of zero
The common-sense interpretation of this bimodality holds that
recruits had two different responses to the tests. Some understood
what they were supposed to do, and performed in varied ways.