152 153
Gain in IQ points1940 1950 1960 1970 1980 1990 2000 2010
30
25
20
15
10
5
0
Is IQ on the rise?
There is evidence for a widespread increase in
IQ. When IQ tests are revised every 10–20 years,
the test-takers who are used to standardize
the new test are asked to take the previous test
as well, and they consistently score higher on
the old test. In other words, if American adults
today took an IQ test from the 1920s, the vast
majority would score in the upper extreme,
above 130. This is supported by evidence from
around the world, although the rate of increase
is most rapid in developing countries. Recent
evidence suggests that this rise, known as the
Flynn effect, has started to plateau.Alternatives to IQ
IQ is not the only measure of intelligence. There are
several alternatives, many of which are more visually
based, with pictures, illusions, or pattern sequences
at their core. Psychometric testing is an approach often
used in job recruitment to assess a person’s aptitudes—
for example, to evaluate empathy when selecting a
carer. People who score well on IQ tests are also likely
to score well on other tests. This probably indicates
a high level of overall cognitive ability, sometimes
referred to as general intelligence factor (g).13.6% 2 .1% 0.1%
130 145
WELL ABOVE
AVER AGE
GENERAL
INTELLIGENCE
(g)VERBAL SPATIAL
MECHANICAL
NUMERICAL
UPPER EXTREME
Claims of exceptional IQs (including scores over
200) are often made but rarely verified. The
American Marilyn vos Savant held the IQ record
(228) in the Guinness World Records from 1986
to 1989, after which Guinness retired the
category because it concluded the tests were
not reliable enough.
Attempts have also been
made to measure the
IQs of people who can
no longer be tested.
Albert Einstein, for
example, is estimated
to have had an IQ
of over 160.RECORD IQS
General intelligence
The ability to do well
across several specific
areas of intelligence
is indicated by
the general
intelligence factor.The Flynn effect
In the US, there has been an average
increase of 3 points per decade in IQ
scores since the mid-20th century.Members of the organization
Mensa have an IQ of about
132 or moreUS_152-153_Measuring_Intelligence.indd 153 20/09/2019 12:37