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

five children.

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

excellent method."

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

standardized tests.

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.