Category: Intelligence

These household products might be doing lasting damage to fetal development.

Routine exposure to common plastics, cosmetics, and household cleaners during pregnancy is linked to lower IQ scores in children.

Mothers with higher exposure to endocrine-disrupting chemicals during their first trimester gave birth to children who scored lower on IQ tests at age seven.

The suspect chemicals include:

• Bisphenol A (BPA) and bisphenol F (BPF), a components of plastic containers used for food and drink.
• Pesticides.
• Phthalates, which are widely used in cosmetics, fragrances and household cleaners.

Both types of bisphenol — the original and the so-called ‘safer’ substitute — had the strongest link to lower IQ in children, researchers found.

Dr Eva Tanner, the study’s first author, said:

“This study is significant because most studies evaluate one chemical at a time; however, humans are exposed to many chemicals at the same time, and multiple exposures may be harmful even when each individual chemical is at a low level.”

Boys affected most

The research included 718 mothers whose blood was tested for 26 different chemicals.

All of the chemicals are thought to disrupt the endocrine system.

This vital system regulates everything from metabolism and growth to sleep and mood.

The results showed that mothers with higher levels of endocrine-disrupting chemicals had children with lower IQs.

Boys were particularly affected, with an average of 2 points lower IQ.

Other chemicals of concern include chlorpyrifos, polyfluoroalkyl and triclosan, which are found in a wide range of consumer products.

Dr Tanner explained the suspected mechanism:

“Some of these chemicals cross the placenta during pregnancy, exposing the fetus and potentially causing irreversible developmental damage.

While ending exposure to a short-lived pollutant may eliminate adverse effects in adults, exposure during critical periods of fetal development may be permanent, with subtle endocrine changes potentially influencing health outcomes into adulthood.”

The study was published in the journal Environment International (Tanner et al., 2019).

The choices people make throughout life may be shaped by a factor that emerges surprisingly early.

People with higher IQs are likely to live longer, according to research.

Those with high intelligence in childhood are less likely to get heart disease, strokes, respiratory diseases and dementia later on.

Higher intelligence may allow people to learn better health behaviours and cope more effectively with problems over the years.

Some of the lowered risk is down to the fact that more intelligent people are less likely to smoke.

The conclusions come from a Scottish study that included 938 people who were followed for over 25 years.

The results showed that each 15-point increase in IQ was associated with a 17 percent reduction in the risk of death.

This study found that the link between IQ and longevity was strongest among children brought up in poorer neighbourhoods.

The findings suggest that higher intelligence may be especially beneficial for the longevity of people from poorer backgrounds, said Dr Carole L. Hart, the study’s first author:

“The significant interaction found between IQ and deprivation suggests that IQ in childhood is less important in terms of mortality for people who live in more affluent areas in adulthood than for people who live in deprived areas.”

It is not yet clear how IQ is related to longevity, said Dr Hart:

“It is possible that low childhood IQ leads to adult deprivation, which in turn leads to earlier death.”

Some studies have suggested that IQ and longevity are linked to the same sets of genes.

Another possibility is that adverse circumstances associated with poverty can reduce cognitive development and lower IQ.

Poor nutrition, limited educational opportunities and disadvantaged neighbourhoods may all hinder mental development.

Other studies have also suggested that higher IQ leads to a longer life.

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The study was published in the journal Psychosomatic Medicine (Hart et al., 2003).

The foods boosts fluid intelligence, which is the speed at which the brain works.

Eating organic food is linked to a higher IQ.

School-age children who ate more organic food had higher scores on tests of fluid intelligence and working memory.

Fluid intelligence refers to how quickly and effectively the brain processes information.

It is like the raw power of an engine or the speed at which a computer functions.

Working memory, meanwhile, is vital to holding pieces of visual, verbal or other information in your mind while you manipulate them.

Better working memory has been linked to improved learning, attention and other vital outcomes.

The higher levels of nutrients in organic foods may account for the boost to IQ, said Dr Jordi Júlvez, study co-author:

“Healthy diets, including organic diets, are richer than fast food diets in nutrients necessary for the brain, such as fatty acids, vitamins and antioxidants, which together may enhance cognitive function in childhood.”

In contrast, eating fast food, exposure to tobacco smoke and overcrowded living conditions were all linked to lower scores on tests of fluid intelligence.

Children’s brains are sensitive

The results come from over one thousand children aged 6 to 11 years old in six different European countries, including the UK and Spain.

The research examined 87 factors that the unborn child might be exposed to, along with another 122 factors that could affect them during childhood.

The brain is still developing in childhood, so it is particularly sensitive to toxicity.

Low levels of toxicity that may have little effect on the adult brain can still influence children’s brains.

Dr Jordi Júlvez, study co-author, explained the main predictors of higher IQ:

“In our study, we found better scores in fluid intelligence and working memory with higher organic food intake and lower fast food intake.”

As for the predictors of lower IQ, Professor Martine Vrijheid, study co-author, said:

“We observed that several prenatal environmental pollutants (indoor air pollution and tobacco smoke) and lifestyle habits during childhood (diet, sleep and family social capital) were associated with behavioral problems in children.”

Professor Vrijheid said the study is notable for its comprehensive examination of a wide range of variables:

“One of the strengths of this study on cognition and the earlier study on behavioral problems is that we systematically analyzed a much wider range of exposure biomarkers in blood and urine to determine the internal levels in the model and that we analyzed both prenatal and childhood exposure variables.”

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The study was published in the journal Environment International (de Bont et al., 2021).

The reason people with a higher IQ also tend to be healthier could be down to their diet.

People with a higher IQ are more likely to be vegetarian.

In fact, vegetarians could be up to 10 percent more intelligent than red meat eaters, according to some studies.

A higher IQ is also seen among those who describe themselves as vegetarian, but also eat chicken and fish.

The conclusion comes from a survey of 8,170 men and women whose IQ was tested when they were 10 years old.

By the age of 30, 4.5 percent of participants had adopted a vegetarian diet.

Within this group, 2.5 percent were strictly vegan, while 33.6 percent identified as vegetarian despite continuing to eat chicken or fish.

People with higher IQs at age 10, the analysis showed, were more likely to be vegetarians at age 30.

There was no difference between stricter vegetarians (ovo-lacto vegetarians) and those who ate some chicken and/or fish as well.

The findings could help to explain why more intelligent people are also healthier, since a vegetarian diet is better for the heart and for maintaining a healthy body mass.

Do money and class explain it?

Part of the link between IQ and vegetarianism was explained by social status and education.

In other words, individuals from higher socio-economic backgrounds are inherently more likely to have a higher IQ and to choose a vegetarian lifestyle.

Nevertheless, even when these two factors were accounted for statistically, the relationship between vegetarianism and IQ remained.

The study’s authors write:

“Might the nature of the vegetarians’ diet in this cohort have enhanced their apparently superior brain power?

Was this the mechanism that helped them to achieve the disproportionate number of higher degrees?

Benjamin Franklin and George Bernard Shaw, both ardent vegetarians, would have us believe so.

According to Shaw in an article published in The Star in 1890, “A mind of the calibre of mine cannot derive its nutriment from cows.”

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The study was published in the British Medical Journal (Gale et al., 2007).

Both men and women are more attracted to a person with this quality.

Being funny is a sign of a higher IQ: both higher general intelligence and higher verbal intelligence.

Making people laugh is also linked to greater dating success, with both men and women more attracted to people who are funny.

However, women are more discerning about humour and react to it more strongly.

Men, meanwhile, tend to focus on producing jokes, often to impress women.”

The study’s authors write:

“Humor is not just a reliable intelligence-indicator; it may be one of the most important traits for humans seeking mates.

Of course, mate attraction is not the only function of humor.

Humor can also be used in competing for status with same-sex rivals, reducing social tensions, and other adaptive functions.”

The study involved 400 young people who were given intelligence tests and asked about their dating history.

They were then handed New Yorker cartoons with the caption deleted and asked to come up with their own.

The results showed that, unsurprisingly, verbal intelligence was strongly related to being funny.

However, participants found it difficult to produce strong captions, with most rated as not funny at all.

This shows how difficult jokes are — especially in the medium of New Yorker captions.

Other studies have also found links between intelligence and humour.

In this study, men were especially focused on trying to write funny captions and theirs were rated more highly, the authors write:

“Men were funnier than women on average and produced a larger number of captions, consistent with the sexual signaling hypothesis in which men try (unconsciously) to signal their mate quality through their humor ability, and women are more responsive to and discriminating about humor.”

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• 10 Lifestyle Strategies That Will Optimise Your IQ (P)
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The study was published in the journal Intelligence (Greengross & Miller, 2011).

How high intelligence could have a mental cost for some.

Disorders of mood could be the price some people pay for high intelligence.

Psychologists have found that higher childhood IQ is linked to features of bipolar disorder in young adulthood.

The research adds fuel to the debate over the connection between intelligence, creativity and mental health issues.

For the research, 1,881 people were followed from age 8 until they were 22 or 23 years old.

Their IQ was measured along with any characteristics of mood disorders.

The results showed that having ten more IQ points  at age 8 was linked to being in the top ten per cent for having manic personality traits in their early twenties.

Professor Daniel Smith, one of the study’s authors, said:

“A possible link between bipolar disorder and intelligence and creativity has been discussed for many years and many studies have suggested a link.

In this large study, we found that better performance on IQ tests at age eight predicted bipolar features in young adulthood.

We are not saying that high childhood IQ is a clear-cut risk factor for bipolar disorder but rather that there is likely to be a shared biology between intelligence and bipolar disorder which needs to be understood more fully.

Many other factors – including family history of mental illness, childhood adversity, stressful life events and drug misuse – are known to increase an individual’s risk of developing bipolar disorder.

Our finding has implications for understanding of how liability to bipolar disorder may have been selected through generations.

One possibility is that serious disorders of mood such as bipolar disorder are the price that human beings have had to pay for more adaptive traits such as intelligence, creativity and verbal proficiency.

This work will inform future genetic studies at the interface of intelligence, creativity and bipolar disorder, and will help with efforts to improve approaches to the earlier detection of bipolar disorder in adolescents and young adults.”

The study was published in the British Journal of Psychiatry (Smith et al., 2015).