Binet's Experiment On How Teachers Test Intelligence
Finally, Binet had three teachers come to his laboratory to judge the intelligence of
children whom they had never seen before. Each spent an afternoon in the
laboratory and examined five pupils. In each case the teacher was left
free to arrive at a conclusion in her own way. Binet, who remained in
the room and took notes, recounts with playful humor how the teachers
were unavoidably compelled to resort to the much-abused test meth
although their attempts at using it were sometimes, from the
psychologist's point of view, amusingly clumsy.
One teacher, for example, questioned the children about some canals and
sluices which were in the vicinity, asking what their purpose was and
how they worked. Another showed the children some pretty pictures,
which she had brought with her for the purpose, and asked questions
about them. Showing the picture of a garret, she asked how a garret
differs from an ordinary room. One teacher asked whether in building a
factory it was best to have the walls thick or thin. As King Edward had
just died, another teacher questioned the children about the details of
this event, in order to find out whether they were in the habit of
reading the newspapers, or understood the things they heard others read.
Other questions related to the names of the streets in the neighborhood,
the road one should take to reach a certain point in the vicinity, etc.
Binet notes that many of the questions were special, and were only
applicable with the children of this particular school.
The method of proposing the questions and judging the responses was also
at fault. The teachers did not adhere consistently to any definite
formula in giving a particular test to the different children. Instead,
the questions were materially altered from time to time. One teacher
scored the identical response differently for two children, giving one
child more credit than the other because she had already judged his
intelligence to be superior. In several cases the examination was
needlessly delayed in order to instruct the child in what he did not
The examination ended, quite properly for a teacher's examination, with
questions about history, literature, the metric system, etc., and with
the recitation of a fable.
A comparison of the results showed hardly any agreement among the
estimates of the three teachers. When questioned about the standard that
had been taken in arriving at their conclusions, one teacher said she
had taken the answers of the first pupil as a point of departure, and
that she had judged the other pupils by this one. Another judged all the
children by a child of her acquaintance whom she knew to be intelligent.
This was, of course, an unsafe method, because no one could say how the
child taken as an ideal would have responded to the tests used with the
In summarizing the result of his little experiment, Binet points out
that the teachers employed, as if by instinct, the very method which he
himself recommends. In using it, however, they made numerous errors.
Their questions were often needlessly long. Several were "dilemma
questions," that is, answerable by _yes_ or _no_. In such cases chance
alone will cause fifty per cent of the answers to be correct. Some of
the questions were merely tests of school knowledge. Others were
entirely special, usable only with the children of this particular
school on this particular day. Not all of the questions were put in the
same terms, and a given response did not always receive the same score.
When the children responded incorrectly or incompletely, they were often
given help, but not always to the same extent. In other words, says
Binet, it was evident that "the teachers employed very awkwardly a very
The above remark is as pertinent as it is expressive. As the statement
implies, the test method is but a refinement and standardization of the
common-sense approach. Binet remarks that most people who inquire into
his method of measuring intelligence do so expecting to find something
very surprising and mysterious; and on seeing how much it resembles the
methods which common sense employs in ordinary life, they heave a sigh
of disappointment and say, "Is that all?" Binet reminds us that the
difference between the scientific and unscientific way of doing a thing
is not necessarily a difference in the _nature_ of the method; it is
often merely a difference in _exactness_. Science does the thing better,
because it does it more accurately.
It was of course not the purpose of Binet to cast a slur upon the good
sense and judgment of teachers. The teachers who took part in the little
experiment described above were Binet's personal friends. The errors he
points out in his entertaining and good-humored account of the
experiment are inherent in the situation. They are the kind of errors
which any person, however discriminating and observant, is likely to
make in estimating the intelligence of a subject without the use of
It is the writer's experience that the teacher's estimate of a child's
intelligence is much more reliable than that of the average parent; more
accurate even than that of the physician who has not had psychological
Indeed, it is an exceptional school physician who is able to give any
very valuable assistance to teachers in the classification of mentally
exceptional children for special pedagogical treatment.
This is only to be expected, for the physician has ordinarily had much
less instruction in psychology than the teacher, and of course
infinitely less experience in judging the mental performances of
children. Even if graduated from a first-rank medical school, the
instruction he has received in the important subject of mental
deficiency has probably been less adequate than that given to the
students of a standard normal school. As a rule, the doctor has no
equipment or special fitness which gives him any advantage over the
teacher in acquiring facility in the use of intelligence tests.
As for parents, it would of course be unreasonable to expect from them a
very accurate judgment regarding the mental peculiarities of their
children. The difficulty is not simply that which comes from lack of
special training. The presence of parental affection renders impartial
judgment impossible. Still more serious are the effects of habituation
to the child's mental traits. As a result of such habituation the most
intelligent parent tends to develop an unfortunate blindness to all
sorts of abnormalities which exist in his own children.
The only way of escape from the fallacies we have mentioned lies in the
use of some kind of refined psychological procedure. Binet testing is
destined to become universally known and practiced in schools, prisons,
reformatories, charity stations, orphan asylums, and even ordinary
homes, for the same reason that Babcock testing has become universal in
dairying. Each is indispensable to its purpose.