HOW IQ BECOMES IQ
In 1904 the French minister of education, facing limited resources for schooling,
sought a way to separate the unable from the merely lazy. Alfred Binet got the job
of devising selection principles and his brilliant solution put a stamp on the study
of intelligence and was the forerunner of intelligence tests still used today.
He developed a thirty-problem test in 1905, which tapped several abilities related to intellect,
such as judgment and reasoning. The test determined a given child's mental age'.
The test previously established a norm for children of a given physical age. For example,
five-year-olds on average get ten items correct, therefore, a child with a mental age
of five should score 10, which would mean that he or she was functioning pretty much
as others of that age. The child's mental age was then compared to his physical age.
A large disparity in the wrong direction (e.g., a child of nine with a mental age of four)
might suggest inability rather than laziness and means that he or she was earmarked
for special schooling. Binet, however, denied that the test was measuring intelligence
and said that its purpose was simply diagnostic, for selection only. This message was
however lost and caused many problems and misunderstandings later.
Although Binet's test was popular, it was a bit inconvenient to deal with a variety of
physical and mental ages. So, in 1912, Wilhelm Stern suggested simplifying this by reducing
the two to a single number. He divided the mental age by the physical age
and multiplied the result by 100.An average child, irrespective of age, would score 100.
a number much lower than 100 would suggest the need for help and one
much higher would suggest a child well ahead of his peer.
This measurement is what is now termed the IQ (intelligence quotient) score and
it has evolved to be used to show how a person, adult or child, performed in relation to others.
The term IQ was coined by Lewis m. Terman, professor of psychology and education
of Stanford University, in 1916. He had constructed an enormously influential
revision of Binet's test, called the Stanford-Binet test, versions
of which are still given extensively.
The field studying intelligence and developing tests eventually coalesced into a
sub-field of psychology called psychometrics (psycho for ‘mind' and metrics for 'measurements').
The practical side of psychometrics (the development and use of tests) became widespread
quite early, by 1917, when Einstein published his grand theory of relativity,
mass-scale testing was already in use.