Flynn’s initial 1984 study1 revealed a 13.8-point increase in IQ scores in the US population between 1932 and 1978, amounting to a 0.3-point increase per year. This phenomenon was confirmed in other countries including Canada and different European nations, although the rate increase seemed to vary according to country and type of IQ test conducted.
The Flynn effect implies that an individual will likely attain a higher IQ score on an earlier version of the same IQ test rather than on the current version (IQ tests are updated periodically). There are multiple hypotheses for the Flynn effect, including improved nutrition, better education and employment and a more stimulating environment. It is noteworthy that today, more adults are accessing better education, including scientific subjects. These involve testing a hypothesis, using abstractions and using the latter logically. In tandem, employment is also becoming cognitively more flexible. A family doctor living a couple of decades ago did not have access to today’s technological armamentarium. And do you imagine a 19th century banker coming up with the infamous credit default swaps and collateral debt obligations (these heralded the recent economic recession which we are still experiencing today).
Other interesting theories supporting the Flynn effect include contraception and the eradication of childhood diseases. Contraception has led to smaller families in recent decades. This means that having for example two children rather than a dozen or so which our grandmothers bred, in turn provides for more adult-child interaction, attributed to lead to enhanced stimulation of the mind, better communication skills and higher IQ. On the other hand, the reason as to why the eradication of childhood diseases seems to improve IQ is that from an energetics standpoint, a sick child will have difficulty developing a brain in view of the fact that convalescence and ontogenesis of the brain are both very taxing metabolically.
However, interestingly, since the mid-1990s we are experiencing a decline in the average IQ in France, Norway, Denmark, Australia, Sweden and the Netherlands. This was also found in the UK.2 This may be partly caused by the large numbers of non-European immigrants [attributed to have lower IQs3] who settled in these countries from the mid-1960s onwards. As an example, at the end of the first decade of the 21st century, 13.1% of the Norwegian population were non-European, as were 11.4% in Denmark, 21% in the Netherlands, 11% in the UK, and approximately 20% in Australia. These non-Europeans, with the exception of the Chinese, have average IQs ranging from 10 to 30 points lower than the European average.3 This could partly explain the decline in IQs in Western European nations.
Interestingly, following a study conducted between 1997–2009, this so called negative Flynn effect has also been reported in Finland even though the influx of immigrants during that period was small. In this case, dysgenic fertility is probably to blame. Dysgenic fertility relates to the environmental influences that cause more intelligent people to have fewer children and less intelligent people to have more children, possibly arising from the manner in which welfare systems are established.
The UK thus seems to experience a declining IQ score, which is reportedly partly attributed to the cohort of naturalised non-European immigrants.3 The question which I ask is whether this contributed, to some varying extent, to the 6.8% swing in the recent Brexit referendum in favour of the Leave campaign (which effectively pledged to curb migration from within the European Union). Against this backdrop, it is worthwhile factoring the surprising allegiance which was pledged by a significant segment of immigrants to Marine Le Pen, the xenophobic leader of the conservative political party in France. Further analysis on this effect is warranted.
- Flynn JR. The Mean IQ of Americans: Massive Gains 1932 to 1978. Psychol Bull. 1984; 95(1):29-51.
2. Shayer M, Ginsburg D, Coe R. Thirty years on - a large anti-Flynn effect? The Piagetian test Volume & Heaviness norms 1975-2003. Br J Educ Psychol. 2007;77(Pt 1):25-41. 3. Lynn R,Vanhanen T. Intelligence: A Unifying Construct for the Social Sciences. London: Ulster Institute for Social Research; 2012.