Intelligence tests were developed for the Army in World War
I. The army had a problem: how to filter out those potential recruits who
simply weren’t smart enough to do any useful job in the army, and how to do it
before the army had wasted valuable time and money trying (unsuccessfully) to
train them. In the intervening years considerable work has been done to improve
and tune these tests. Of course they are only a rough measure of intelligence,
since human intelligence is expressed in many subtle and individual ways, not
all of which are captured by the tests. Nevertheless, as a gross measure of
intelligence the tests are pretty good despite what some critics argue.
Now intelligence is “normally distributed” in the population.
That means, measured over large groups of people, it tends to be distributed in
a Gaussian or “bell shaped” curve, just like some other attributes, like
height or weight. Most people are clustered
around the middle, with a diminishing proportion in the tails, either much less
or much more intelligent.
Intelligence tests are standardized so that the mean score
(the middle) is 100. There is a measure (I won’t define it. You can look it up
in Wikipedia if you want the details) called the “standard deviation” which divides
the normal distribution, and intelligence tests are standardized to have a
standard deviation of 15. Each colored bar above is 1 standard deviation.
The diagram shows what proportion of the population falls
into each area. For example, 34% of people will have an IQ between 100 and 115,
and 68% will have an IQ that falls somewhere between 85 and 115. Similarly, only 2% of the population will be
in the 130-145 range (the gifted range) , and only 0.1% above 145 (the genius range).
Now in World War I the American army found that potential
recruits more than one standard deviation below the mean (IQ of 84 or less)
simply were not useful in the army, and so were not accepted for service. These
days the armed forces use the Armed Services
Vocational Aptitude Battery (ASVAB) for the same purpose.
In general it takes an IQ of about
115 or above to successfully do demanding undergraduate level college work (not
counting the dumbed-down courses some colleges have created for their more intellectually-challenged
athletes). But no doubt a few people with lower IQs who are hard workers and persistent
also make it – persistence and hard work is a great equalizer. A postgraduate degree
in science or math may well take more than that.
Now when Bernie Sanders proposes “college
for all” this is the reality his proposal faces – less than 20% the population
has the intellectual capacity to do demanding college level academic work, and some of those probably aren't interested or temperamentally suited to academic work. We ought
to have, as many European countries do, an alternate apprentice or trade school
route, equally valued in society, for the other 80+ % of the population, many of
whom would be excellent, and could earn a good living, at many non-academic
trades. Unfortunately we have developed a snobbishness among our elite (including
the media) which only values a college education. Note that currently about 30% of Americans have at least a 4-year college degree, but then colleges have added a lot of less academically demanding courses, as well (under pressure from college administrators) as skewing grading standards to produce more graduations so that the college ranks higher.
Similarly, when one looks at some
of the absurd things people will believe, especially from their politicians, keep
in mind the curve above. Half the population, including roughly half the vote-eligible
population, falls below the mean IQ of 100.
Now this is a touchy subject,
probably politically incorrect in some liberal circles, but it is reality nonetheless,
and it is a reality we badly need to come to terms with. In an increasingly
technological world, where an increasing proportion of jobs require more than
average intelligence, what is to become of the massive proportion of the
population that cannot cope? Once upon a
time a less intelligent person could still get a job as, say, a ditch digger. Have you seen ditches being dug today? The “ditch
digger” will be a highly skilled machine operator sitting on top of a
quarter-million dollar machine. Even the intellectually unchallenging (but not necessarily
easy) assembly line jobs are now largely done by robots.
It’s clear we as a society need
to do at least two things: (1) stop assuming that only college graduates are worth
hiring, and (2) think hard about how the less intellectually endowed among us
can find valued work that pays a living wage in an increasingly technological
world.
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