King's College UK: The Flynn effect predicts that scores on intelligence tests will
increase year-on-year and this effect, first coined in 1994, has been
given a boost by a new meta-analysis from researchers at the Institute
of Psychiatry, Psychology & Neuroscience (IoPPN) that included
scores from over 200,000 participants.
Peera Wongupparaj, a research student in the Department of
Psychology, investigated changing IQ scores in 48 countries across the
world and over a 64 year time period and concluded that the Flynn effect
holds up in each of the five age groupings used as well as in different
nations. In low income countries, the Flynn effect was observed to a
greater degree than in high income countries over the period and
although the reasons for this larger increase are not clearly
established, potential causes include improved education, medical care
and nutrition, modernised child rearing, increased exposure to testing
and even the use of artificial lighting. As a result of the accelerated
Flynn effect in low income countries, the gap between the average IQ in
low income and high income countries has narrowed and now stands at just
below three points.
“Defining the different type of countries is an issue for this
type of study and so we based high/low income countries on recent
International Statistical Institute criteria that considered on their
Gross National Income (GNI) per capita per year,” said Peera.
“Accordingly, we were able to include in the meta-analysis 532 studies
from high income and 198 from low income countries.”
The Flynn effect is named after James Flynn, Emeritus Professor of
Political Studies at the University of Otago, New Zealand and was
coined by Richard Herrnstein and Charles Murray in their controversial
1994 book The Bell Curve. The concept of the Flynn effect is that
performance on IQ tests improves over time in new sample populations.
When an IQ test is originally calibrated the Intellectual Quotient (IQ)
is set such that 100 represents an average score. In part, because of
the Flynn effect, this calibration has to be done again every so often
to take into account the changing performances. The work by Peera,
supported by his supervisors at the IoPPN Professors Robin Morris and
Veena Kumari, has made a major contribution in confirming this effect
using newly applied statistical techniques, and a key conclusive finding
that it is the accelerated Flynn effect in low income countries.
Peera said: “We used a novel statistical technique in this context
called Cross-Temporal Meta-Analysis, which allows for the bias in such
studies caused by varying sample sizes and within-study variance, and
applied this technique to Raven’s Progressive Matrices IQ data taken
from published articles during 1950 to 2014.”
Professor Robin Morris said: “This study clearly now confirms the
Flynn effect beyond reasonable doubt and the manner in which
intellectual test performance is catching up in low income countries.
The challenge, of course, is to define more clearly why the increases
have been taking place.”
Paper reference: Wongupparaj, P, Kumari, V and
Morris, R G ‘A Cross-Temporal Meta-Analysis of Raven's Progressive
Matrices: Age groups and developing versus developed countries’
published in Intelligence DOI: 10.1016/j.intell.2014.11.008
For further information contact Tom Bragg, Press Officer
at IoPPN, King’s College London, on +44(0)2078485377 or email
ioppn-pr@kcl.ac.uk