Intelligence is a great gift for human beings, and not all of us know how to use it as we should.

Everyone is more or less intelligent, unless they suffer from some kind of disorder that involves a significant decrease in intelligence.

Anyway, here we will see several curiosities about intelligence , as well as explaining some interesting theories and characters related to it.

20 curiosities about human intelligence

Next we will see 20 curiosities about this construct, plus some interesting data about people who, in one way or another, have been known to have great cognitive abilities.

1. The tests do not measure intelligence in absolute terms

Contrary to what many people believe, intelligence questionnaires are not an unequivocal indication of a person’s intelligence . They measure intelligence in relative terms.

When it comes to answering them, there may be influences from factors such as mood, what you have eaten that day or tiredness that may impair performance when answering the items that make them up.

2. Intelligence may not be one-dimensional

According to Howard Gardner’s proposal, it would not be one but several the intelligences that human beings possess .

This conception, called the Theory of Multiple Intelligences, defends that there are various intelligences depending on the different types of problems one has to face.

So we would talk about up to eight intelligences: linguistic-verbal, logical-mathematical, spatial, musical, corporal, intrapersonal, interpersonal and naturalistic.

Since its formulation, this theory has been highly questioned, but there are other explanatory models of intelligence which distinguish between various groups of cognitive abilities, while not denying the existence of a basic form of unitary intelligence.

3. Intelligence is usually stable over time

Practicing always helps to improve and master a certain skill, such as playing chess, or knowing a lot about such a complex subject as quantum physics. However, this does not mean that the person’s IQ is increased.

We can develop skills and acquire new knowledge throughout our lives, but what we will not be able to do is modify our intelligence much and quickly , which tends to remain stable.

4. There is no single gene behind intelligence

It is not uncommon to believe that intelligence is something that is due to one or more genes. This corresponds to a very unitary view of intelligence. But intelligence, in itself, is nothing more than a social construct and, therefore, it is not possible to find a single biological factor behind it .

It would be rather the result of a set of processes, related to the development of the different brain areas, their efficiency at work, having been exposed to environmental elements that influence the IQ…

5. The smartest person alive

The most intelligent living person on record is Terrence Tao, with an IQ of 230 .

He is a mathematician, and is working at UCLA, having the honor of being the professor who started working at the institution with the youngest age of all, at 24.

6. The most intelligent person of all time

To date, the person who has been attributed the highest IQ score in all of history is William Sidis (1898-1944), who would be the most intelligent person of all time.

In 1933 he was given an intelligence test and, based on later estimates, he has been awarded an IQ of between 250 and 300 points.

7. White people are not smarter

From very racist perspectives, ancient science tried to show that white people were significantly smarter than those of African, Asian, or Native American races. These claims were based on the anatomy of the skull according to race, cultural differences, and, of course, the fact that whites were the masters and blacks the slaves in countries like the United States.

During the last century, intelligence questionnaires showed that black people had, on average, 10 to 15 fewer IQ points than white people, giving strength to the above claims.

However, later reviews of the questionnaires used showed that they were markedly culturally biased , making them invalid for people raised in significantly different settings than white people.

After correcting these failures and reapplying these same questionnaires, no differences between races have been found in relation to intelligence.

8. Left-handed people are not smarter than right-handed people

Given that great figures of history, such as Leonardo da Vinci, Michelangelo, Isaac Newton, Benjamin Franklin and others were left-handed, it has always been believed that having the left hand as the preferred hand could be related to genius.

However, it has been seen that this is not the case, and it has been possible to address it scientifically. A study carried out at the University of Adelaide, with a sample of 5,000 people, analysed the academic development of school students to see if there were differences between left-handed and right-handed people .

No significant differences were found to show that left-handed people were smarter. Furthermore, it was noted that there was a belief that left-handed people were less successful in studies, although this was also not true.

9. Women are not less intelligent than men

Over the last 100 years, women’s IQs have increased significantly when answering intelligence questionnaires.

This is not because there has been a real increase in their cognitive capacity, but, similar to the case of race differences, the questionnaires were made by men who developed them with a marked gender bias.

Women did not receive the same type of education as men , and if we consider that the questionnaires incorporated aspects traditionally taught to men, such as mathematics, it is logical to understand this.

As tests have been developed that are less biased by these aspects, performance on these tests between men and women seems to have progressively equalized.

10. Mind games do not increase intelligence

There is a general idea that clever entertainment, such as sudoku, crossword puzzles or similar games, increases intelligence.

This really isn’t like that. Not by doing 20 sudokus in a row you will magically increase your IQ by 10 points.

However, this type of game is quite useful for people who want to spend time testing their intelligence , and is especially recommended for those who suffer from some kind of dementia or brain damage.

11. Breastfeeding slightly improves intelligence

Differences in IQ have been found among people who were breastfed, that is, fed their own mother’s breast milk, compared to those who were given a bottle.

According to several studies, in some cases breastfeeding and not breastfeeding would result in differences of about 4 IQ points.

12. Processed food diets

Diet, as an environmental factor, seems to influence the IQ .

It has been seen that diets that include foods that have been processed and include artificial flavors make you perform less well when answering intelligence questionnaires.

13. Albert Einstein’s Brain

While this is not a curious fact about intelligence per se, it does have to do with one of the most intelligent people in history, as well as having a great influence during the first half of the last century.

When he died, Einstein’s brain was kept in a jar by a pathologist to see anatomical features of this organ and relate them to the genius of the living scientist.

Albert Einstein’s brain weighed 1,230 grams, about 10% less than the usual human brain weight of about 1,400 grams. However, the neural density of the scientist’s organ was higher than average.

14. Savant’s syndrome

The Savant’s syndrome, also called the Wise Man’s syndrome, is a condition in which the person, according to Darold Treffert who coined it, has a remarkable intellectual talent but, sometimes, does not have to have a real practical application .

These skills can include photographic memory, learning languages very easily or remembering all the tiles that make up a street.

15. Are savants born savants?

Many savants are savants from the time they were born, however, others may be savants due to having suffered some type of head trauma which, fortunately, gave them outstanding intellectual ability rather than having a serious clinical symptom.

16. Brain plasticity and intelligence

Although it is true that intelligence is a construct that remains more or less stable throughout life, this does not mean that the brain cannot modify its structure throughout development or that new neurons cannot be generated.

This clashes with what was believed until relatively recently, since it was argued that neurons could no longer reproduce to a certain extent .

The human brain possesses plasticity, which allows it to acquire new learning throughout the subject’s life, through changes at the neuronal level (neurogenesis) and structural level, albeit slight.

17. The Myth of the Mozart Effect

If you do a quick search on platforms such as YouTube and put in the search engine classical music, such as Mozart, Beethoven or Vivaldi, you will see that many videos will appear in which you ensure that listening to them increases intelligence.

This is because, according to the Mozart effect, listening to classical music, especially that of this 18th century Viennese artist, improves memory and concentration, and if listened to while pregnant, it increases the IQ of the future baby.

This is all terribly false. Mozart, without taking away what a great musician he was, did not create symphonies that had the magic power to change aspects at a cognitive level , although it is advisable to listen to it.

18. We don’t use 10% of our brain

In films such as Luc Besson’s ‘Lucy’ (2014), it is said that, normally, human beings only use 10% of their brain and that, if this percentage were increased, they would achieve a much higher intellectual capacity.

This is not so. If brain scans are analysed, using neuroimaging techniques, it is possible to see that the brain activity is clearly higher than a simple 10%, even when sleeping .

19. Flynn effect

The Flynn effect is the continuous, year-on-year increase in IQ seen in most countries of the world , especially those who have jumped on the bandwagon of socio-economic development.

Since the 1930s, there has been a 2 to 3 point increase in the UK population IQ every ten years.

This is associated with better nutrition, accompanied by smaller families and better control of children, as well as improvements in education systems and healthier environments.

20. Dehydration affects intelligence

It is not that being dehydrated diminishes intelligence in any strict sense of the word, but it does make us less efficient at solving problems of any kind.

Dehydration of 2% is enough to cause difficulties in performing tasks that require attention, psychomotor skills and working memory .

It never hurts to carry a bottle or canteen full of water with you. Let’s not get less clever for a while…

Bibliographic references:

  • Laskowski, K. and Henneberg, M. (2013). Writing with non-dominant hand: left-handers perform better with the right hand than right handers with the left. Anthropological Review, 75(2): 129-136.
  • Gardner, H. (1998). “A Reply to Perry D. Klein’s ‘Multiplying the problems of intelligence by eight'”. Canadian Journal of Education 23 (1): 96-102. doi:10.2307/1585968. JSTOR 1585790.
  • Horta, B. L., Loret de Mola, C. & Victora, C. G. (2015). Breastfeeding and intelligence: a systematic review and meta-analysis. Acta Paediatrica, 104: 14-19.