Why IQ Test Scores Are Slightly Decreasing: Possible System-Based Explanation for the Reversed Flynn Effect

Why IQ Test Scores Are Slightly Decreasing: Possible System-Based Explanation for the Reversed Flynn Effect. Griselda Acosta, Eric Smith, and Vladik Kreinovich. Technical Report UTEP-CS-19-61, July 2019. http://www.cs.utep.edu/vladik/2019/tr19-61.pdf

Abstract: Researchers who monitor the average intelligence of human population have reasonably recently made an unexpected observation: that aftermany decades in which this level was constantly growing (this is knownas the Flynn effect), at present, this level has started decreasing again. Inthis paper, we show that this reversed Flynn effect can be, in principle, explained in general system-based terms: namely, it is similar to the fact that a control system usually overshoots before stabilizing at the desiredlevel. A similar idea may explain another unexpected observation - that the Universe's expansion rate, which was supposed to be decreasing, isactually increasing.1 Formulation of the Problem IQ tests: a brief reminder.

For many decades, researchers have been using standardized test to measure Intelligent Quotient (IQ, for short), a numerical values that describes how smarter is a person that an average population:

.the IQ value of 100 means that this person has average intelligence,
.values above 100 means that this person's intelligence is above average,and
.values below 100 means that this person's intelligence is below average.1

Of course, this is a rough estimation. Researchers have known that there are different types of intelligence, and that it is therefore not possible to adequately characterize one person's intelligence by using a single number. However, the IQ test score remains a reasonable overall (approximate) measure both of the individual intelligence and of the relative intelligence of different population groups. For example, a recent study showed that non-violent criminals are,on average, smarter than violent ones; this makes sense, since it takes someintelligence (ill-used but still intelligence) to steal without using violence.Average IQ scores grow: Flynn's effect.

Since the IQ scores describethe relation of a tested person's intelligence to an average intelligence at thegiven moment of time, researchers periodically estimate this average level of intelligence.

Somewhat unexpectedly, it turned out that for almost 100 years, the averagelevel of intelligence has been growing; see, e.g., [2, 4, 5, 8, 9, 11, 15, 18, 21]. Specifically:

.if we give average current folks the test from the 1930s, they will, onaverage, score way above 100, and
.vice versa, if we measure the intelligence of the 1930s folks in a currentscale, their average intelligence will be way below 100, at about the 80-90level.

This steady increase in intelligence is known as the Flynn effect, after a scientist who actively promoted this idea.

Why IQ scores grow: possible explanation.
There are many explanations for the growth in intelligence. One of the natural ones is that, in contrastthe old days, when in many professions, physical force was all that is neededto earn a living, nowadays intelligence is very important . non-intelligent jobshave been mostly taken up by machines. No one needs a galley slave to rowa boat, no one needs a strong man to lift heavy things, etc. It is thereforereasonable that modern life requires more intelligent activities, and this increasein solving intelligent problems naturally leads to an increased intelligence . justlike exercising the muscles leads to an improved physique.

Reverse Flynn effect.
While the intelligence scores have been steadily risingfor several decades, lately, a reverse phenomenon has been observed, when theaverage scores no longer grow; instead, they decline. This decline is not as bigas to wipe out the results of the previous decades of growth, but it is big enoughto be statistically significant; see, e.g., [1, 6, 7, 10, 13, 14, 16, 17, 19, 20].

How can we explain the reverse Flynn effect?
There are many differentexplanations for the reverse Flynn effect: that it has been caused by pollution,that it has been caused by declining education standards, etc.In this paper, we analyze this phenomenon from the general systems view-point, and conclude that, from the system.s viewpoint, a current small decline isnatural - and that we therefore do not need to be unnecessarily alarmed by this2 decline. In other words, in spite of this decline, it is still reasonable to remain optimistic.