The difference between intelligence and IQ is that intelligence is the real, underlying psychological function, whereas IQ is a score achieved in a test – a score which is intended to compare and measure intelligence but which is an indirect, only partly-precise and only partly-valid measure of intelligence. The IQ test is clearly a sound measure of intelligence – because IQ scores correlate with other measures of cognitive problem solving ability and thus brain functioning – but it is imperfect, meaning other factors than intelligence can impact the score. In much the same way, a bathroom scales measures weight – its results correlate with other measures of weight – but some scales are better than others and no scales is perfect.
Therefore, we can think of a qualitative, subjective
understanding of the phenomenon of real intelligence as an irreducible entity – not understood in terms of other things
nor only in terms of what it does,
but in terms of itself as a real thing
which we can detect and measure only indirectly. And we can then conceptualize
IQ as the practical, simplified, publicly-shareable way of conceptualizing and
investigating intelligence.
IQ can be, and usually is, researched in a ‘theory-free’ fashion,
with operational definitions based on proxy description, measurement by
comparison, and correlation – indeed intelligence is sometimes asserted to be
nothing-more than a mathematical-derivation from IQ scores.
But we would emphasize that to understand intelligence
requires understanding that sometimes a person may be of high intelligence and not have
a similarly high IQ score (in other words, their IQ score is under-estimating
their intelligence) – and that this may be the case no matter how validly, how often
and how carefully the IQ is measured and calculated. And another person may
have high IQ scores, measured in the best ways and by the best methods, yet not be of
similarly high intelligence (in other words, their IQ score is over-estimating their intelligence).
Highly intelligent people who do not score as highly on IQ tests are
easy to understand – because anything which reduces test performance could lead
to this outcome: illness, pain, impaired consciousness and impaired
concentration from sleepiness, drugs, drug-withdrawal, mental illness ... there
are multiple causes, and some are chronic (long-lasting, perhaps life-long).
And people with high IQ scores who are not of similarly high intelligence to
their scores are familiar to anyone who has attended a highly-selective college
or educational programme or who are members of intellectually ‘elite’
professions; since they typically make-up a large proportion of participants.
The ‘Flynn Effect,’ named after its discoverer New Zealand psychologist James
Flynn, refers to the phenomenon of rising average IQ scores over the twentieth
century in Western countries. The fact that this has taken place in a context
of declining average real-intelligence means that the Flynn Effect can indeed
be understood as evidence that IQ tests measure issues other than just
intelligence, meaning they are imperfect.
(Plus, even the most reliable IQ test only has a
reliability of about 0.9 when retesting the same person.)
One possible explanation for the Flynn Effect, proposed by
Flynn himself, is that modern society – due to higher levels of education in
the general population – makes us think in a more scientific way and this
ability is partially a reflection of intelligence and partially of a separate
ability that does not rely on intelligence.[1] As such, IQ tests can be used to compare intelligence
within a current population but they cannot be used as easily to make
comparisons over time because they are examinations and people will tend to get
better at them by practicing them and thinking in the way that permits optimum
performance in them as society becomes more educated. So, up to a point, IQ
scores may increase over time, despite the fact that intelligence is decreasing.
After (probably) six or eight generations of rising average
IQ scores and falling real-general intelligence; there has been a progressive
breakdown in the strength of correlation between intelligence measured in terms
of IQ scores, and intelligence understood as a real underlying, brain
functional phenomenon. Indeed, it seems likely that many or most people among modern
high IQ scorers do not have similarly
high real-intelligence. This would be expected to apply especially at
highly-educationally-selective institutions where Endogenous personalities are
substantially selected-out by the decades-long trend for an increasingly-high
minimum-threshold of conscientiousness imposed by educational qualifications.
The correlation between IQ score and ‘g’ was probably much higher
in the past (a century plus ago) than it is now – meaning that the distinction
between IQ score and real, underlying intelligence is more important now than
it used to be.
[1]
Flynn, J. (2012). Are We Getting Smarter?
Rising IQ in the Twenty-First Century. Cambridge: Cambridge University
Press.
