At the end of the 20th century, there was a worldwide trend for IQ test scores to increase when comparing successive generations. This phenomenon is known as the Flynn effect. and is particularly important in populations of low socio-economic status.
However, increases in CI due to the Flynn effect have recently diminished in rich countries, to the point that other factors have overtaken it, so the current trend in these regions of declining intelligence is average.
What is the Flynn effect?
Researcher James Robert Flynn (1934-) has defended during his career the fact that intelligence depends largely on environmental factors, which makes it unnecessary to resort to intergroup explanations, such as the genetic superiority of certain social groups.
The term “Flynn effect” was coined by Richard Hernstein and Charles Murray in the book The Bell Curve (1994). These authors used it to describe the increase in IQ that occurs with generational changes, A phenomenon that has been detected in many parts of the world and that Flynn has helped to spread.
The Flynn effect occurs in fluid, crystallized spatial intelligence and overall IQ, but is particularly noticeable in fluid IQ scores. In the face of crystallized intelligence, which depends on experience, fluid is defined as the ability to solve new problems and is mainly attributed to biological factors.
Several studies and meta-analyzes conducted around the world have confirmed the cross-cultural nature of the Flynn effect. However, it seems to be happening almost exclusively in populations of low socio-economic statusThis indicates in all probability that it is related to environmental factors.
The magnitude of the Flynn effect has also diminished over time, at least in wealthy countries. In addition, there are other phenomena which influence the fact that today the global trend has reversed and is now negative; we’ll talk about that later.
Explanations of this phenomenon
Since the increases in intelligence that were detected occurred too quickly (sometimes up to 10 CI points at age 30) to be due to genetic variations, the explanations proposed for the Flynn effect mainly focus on the environment.
1. Improve schooling
Some authors have proposed that the Flynn effect is simply due to an increase in literacy rates, which are associated with an improvement in CI. On the other hand, access to quality education, especially for children of low socioeconomic status, could also explain part of this phenomenon.
2. Compensation for nutritional deficits
Nutritional deficits they interfere with physical development of children, and therefore also in the cognitive. In places where infant nutrition is inadequate, as was the case in most parts of the world a century ago or in many African countries today, IC scores are generally lower.
It is important to note that these effects overlap with improvements in education after a certain age. In any case, it is believed that nutrition may be more relevant for intellectual development in the very early stages of life.
3. Advances in medicine
Like improving nutritional conditions, advances in medicine have enabled the healthy development of many people. According to some studies, it is particularly important reducing the number of infectious diseases, As well as in its severity; this type of disorder can affect the brain if not treated properly.
4. Enrichment of the environment
Flynn himself defended himself in his book “What is Intelligence?” (2007) that recent changes in society have increased the abstract reasoning capacity of the world’s population. These variations can be primarily technological or social.
Among the relevant factors, Flynn stands out familiarization with new technologies, Which can be brain stimulants, increasing educational and professional demands and decreasing the number of children per family, which would allow for improved care and care that children receive.
5. Knowledge of CI testing
Besides the popularization of CI tests, this factor is linked to increasing literacy rates and improving formal education. Schooling improves the capacity for abstract thinking and therefore allows higher scores on instruments that measure intelligence.
In a similar vein, the test format has grown considerably over the past decades as a form of educational testing, including tests with verbal and mathematical elements very similar to some IC tests. It may also have influenced familiarity with this type of test.
Are we getting smarter and smarter?
Although the Flynn effect remains significant at low socioeconomic levels and in poor countries, studies conducted over the past decades confirm that the influence of this phenomenon is decreasing overall. That means currently the average CI level tends to drop, Even retaining the Flynn effect.
According to various research, the Flynn effect has been overtaken by other factors that promote a reduction in the average IC in countries like UK, Norway, Denmark or Australia. Experts further predict that this decline will continue at least for the rest of the 21st century in Europe and the United States, if the current trend continues.
However, the increase in intelligence is expected to continue in areas where the needs of the population are met to a lesser extent, such as Latin America, East Asia, Arab countries, Africa and India.
The exact causes of this phenomenon have not yet been determined. There are those who link it to the arrival of immigrants from countries with a lower average IQ, but research does not support this hypothesis. Historically, the decline in intelligence has been attributed to the fact that people with higher IQs tend to have fewer children.