Younger generations are more intelligent

Every year, each new generation is achieving better results in IQ tests. Right now, we are getting beaten by the younger. We also beat our parents, and they did the same with our grandparents. This effect, discovered in 1984, is called the Flynn effect (after the researcher that first discovered it).

So far, it has been demonstrated in every “inhabited continent”, age, and population -rich to impoverished-. The effect seems to be a bit more concentrated on low IQ persons. That is, IQs between 71 and 80, creating the so-called zone of ambiguity.

Again and again, new teams of researchers are replicating the results. And this effect is not becoming just accepted. It is deciding important matters such as life and death in courtrooms. 

Your mind might be boiling right now. So does this mean that your older brother is less intelligent than you? But your younger sister more intelligent? Maybe, let's see.

First, the effect is now widely accepted to mean that every year, people will achieve 0.3 more points than the people born the year before. Of course, that is if they were to do all the same IQ test. In other words, people born 10 years later obtain 3 more IQ points in the same IQ test, on average. 

We say on average because we are talking about the aggregation of all. IQ is calculated by comparing your performance against everybody else’s. So, your older brother might be super intelligent and therefore beat you. But if you compare your older brother’s generation with your generation, well…, yours is more intelligent. The effect applies to generations.

Let’s say you were born in 1995, whereas I was born in 1985, my 120 IQ would just equate to a less lustrous IQ of let’s say 117 with your generation. 

What are the causes for these IQ gains?

Some scientists have claimed that the secret sauce to gain IQ every year lies within our genes. The more we inter-mate, the better genes we have. But later studies have mostly disproved this. 

It seems however that the strongest hypothesis can be found in our environment. It is thought that nutrition and care in prenatal and young ages could play a very strong factor. 

Keep in mind that younger generations don’t have only higher IQs, but more height and weight. Haven’t you found yourself thinking: What are these young folks eating, they are as big as monsters? Yeah, me too.

Another factor is our education and scientific thinking style. We are more prepared than ever for a formal-operational way of thinking that could increase performance in these types of tests.

This matches well with the fact that the effect has been found mostly when measuring fluid intelligence (e.g., induction, deduction) and not the crystallized intelligence related to education. 

As such, vocabulary sub-tests for example have barely seen any big gain. This has led many experts to clarify that it is not general intelligence what is growing, but skills in some areas.


Some countries are seeing their IQs decrease

Yet things are more complex than thought. In several advanced countries the contrary effect has been discovered in recent years -so-called anti-flynn effect-. In some of the most advanced countries, IQs were decreasing or simply plateauing. An example is Denmark, an scandinavian country with great education and social welfare. 

Why would IQs decrease? Some scientists think that we have reached the peak of education and biology. But the answer seems to be easier than expected. Among all possible causes (test items obsolescence, poorer nutrition, contamination, and so on), a powerful study from 2018 (see Woodley et al. study in our references) found that the main factor was immigration. 

Countries with powerful economies and strong immigration have been receiving population that has been exposed to worse conditions in their home countries during their upbringing. Hence their average IQ was lower in comparison with their new country-fellows, decreasing the average of the new country. 

At the same time, since the people that could and did emigrate constituted mostly the above average IQs, even if they were below average in the receiving country, they have also decreased the average IQ of their home countries. This has been found in countries such as Brazil or South Africa.

When a small IQ difference can mean life or death

You might think, Ok, but is this important? Well, yes! A lot. This effect has massive implications when we are talking about daily-life decisions such as educational admissions, special education, job recruiting, but even more with high-stake decisions, such as the death row. 

Was the accused really mentally retarded? If yes, he cannot be sentenced to death. Usually, defendants’ forensic psychologists will diagnose retardation -to save the defendant’s life- while the prosecution’s psychologists will say no, was not retarded. Courts therefore try to use an objective measurement tool to decide, and that is IQ tests. 

Let’s imagine such a case. The accused, let’s call him Joe, was suspected of being mentally retarded when he was a child. He took an IQ test when 17 years old, scoring an IQ of 72.

Precisely 70 is the traditional threshold for mental retardation (two standard deviations from the mean). If higher, the person is not retarded, if lower than 70, it is retarded. So the teacher decided that he was not. 

Coming to the present, Joe has killed two persons in a robbery and he is confronting the possibility of execution. The defense has an idea to avoid it. Joe did a test which was standardized ten years before he took it, so his IQ, in comparison to the average population at the time he took the test, should have been lowered 3-points, that is to 69. That would mean life. 

No surprise then that this has been an issue that the Courts have looked into, for example in the United States. There is pretty much a consensus that the Flynn effect is sufficiently proved and therefore the Courts must do calculations to find the real IQ of the person at the time of taking the test (as the 4th Circuit Court of Appeals opinion of Walker vs True of 2005 stated). Also, behavior as well as the possibility of measurement errors should be taken into account, say the Courts. Daily moods, general health and so on are weighed on the final decision, as they can also alter an IQ test result to a small degree. In this case, the good lawyers saved Joe’s life.  

How can I calculate my IQ corrected by the Flynn effect?

It’s pretty simple. Let’s follow Flynn’s explanation. Simply multiply 0.3 points by the years that have passed since the test was standardized or sampled. For example, if 10 years have passed, it would be 3 points. Then deduct these points from the IQ that you obtained. If you obtained 120, your IQ 10 years later is 117. 

What happens if I do not know when it was standardized? Well, an easy option is to only count the years since you did that IQ test. It’s an approximation but should be more than acceptable.

All in all, my IQ of 100 (average) that I obtained when I was 30 is going to be equivalent to 91 when I am 60. On one hand, it hurts my feelings. But on the other hand, it is pretty emboldening to think that humanity is advancing and the world will be more skilled than it is now. Right?