Category: Intelligence

The study of almost 10,000 people used MRI scans to measure abdominal fat and blood flow through the brain.

Higher body fat is linked to the brain being slower to process information — a critical component of IQ.

The more abdominal or ‘belly fat’ that people have, the lower their scores on tests of cognitive function.

The study of almost 10,000 people used MRI scans to measure abdominal fat and blood flow through their brain.

Professor Sonia Anand, the study’s first author, explained the results:

“Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function.

The effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function.”

A healthy body weight is key to a healthy brain, said Dr Eric Smith, study co-author:

“Preserving cognitive function is one of the best ways to prevent dementia in old age.

This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage.”

Nutrition and cognitive function

Nutrition is often linked to cognitive function by research.

For example, a study on rats found that high-fat foods can reduce intelligence in just 9 days.

Cognitive performance was reduced by 20 percent in just over a week after eating a high-fat diet.

The study on rats fed them a diet equivalent to human junk food.

Another rat study also found that diets high in saturated fats can slow brain function.

In contrast, healthier diets have repeatedly been linked to better cognitive function, higher IQs and a lower risk of dementia.

For example, people fed a healthier diet from an early age have a higher IQ, one study found.

Even eating organic food in childhood is linked to a higher IQ.

Finally, the MIND diet could lower the risk of developing Alzheimer’s disease by over 50 percent and improve your brain health.

The study was published in JAMA Network Open (Anand et al., 2022).

Scores on IQ tests change dramatically when people feel poor.

Feeling poor causes IQ to drop by around 10 points or roughly 10 percent, a study finds.

Worrying about a lack of money uses up people’s cognitive resources, leaving them less brainpower to deal with other problems in life.

It is not that the poor are less intelligent, explains Professor Sendhil Mullainathan, study co-author:

“Our results suggest that when you’re poor, money is not the only thing in short supply.

Cognitive capacity is also stretched thin.

That’s not to say that poor people are less intelligent than others.

What we show is that the same person experiencing poverty suffers a cognitive deficit as opposed to when they’re not experiencing poverty.

It’s also wrong to suggest that someone’s cognitive capacity has gotten smaller because they’re poor.

In fact, what happens is that your effective capacity gets smaller, because you have all these other things on your mind, you have less mind to give to everything else.

Imagine you’re sitting in front of a computer, and it’s just incredibly slow.

But then you realize that it’s working in the background to play a huge video that’s downloading.

It’s not that the computer is slow, it’s that it’s doing something else, so it seems slow to you. I think that’s the heart of what we’re trying to say.”

In one study the researchers conducted in a mall, low- and middle-income shoppers were given IQ tests.

Half, though, were first asked what they would do if their car broke down and the repairs cost $1,500.

This made poorer people start worrying about money and reduced their scores on the subsequent test by around 10 percent.

Professor Mullainathan said:

“For the poor, because these monetary concerns are just below the surface, the question brings them to the top.

The result was, for that group, the gap between the rich and the poor goes up, in both IQ and impulse control.

There was no gap in the other group, but ask them anything that makes them think about money and you see this result.”

Another study compared farmers in rural India.

Professor Mullainathan explained:

“The month after the harvest, they’re pretty rich, but the month before – when the money has run out – they’re pretty poor.

What we did is look at the same people the month before and the month after the harvest, and what we see is that IQ goes up, cognitive control, or errors, goes way down, and response times go way down.

The effect here is about two-thirds of the size of the effect found in the mall study – it’s at least nine or 10 IQ points, just between these months.”

The study was published in the journal Science (Mani et al., 2013).

The average IQ for the population is 100.

Smoking is a sign of below average IQ, research finds.

The average IQ for young male non-smokers is 101– a score of 100 is the average for the population.

However, smokers’ IQ was a full 7 points lower at an average of 94.

Those who smoked more than a pack a day had IQs around 90.

Professor Mark Weiser, the study’s first author, said:

“In the health profession, we’ve generally thought that smokers are most likely the kind of people to have grown up in difficult neighborhoods, or who’ve been given less education at good schools.

But because our study included subjects with diverse socio-economic backgrounds, we’ve been able to rule out socio-economics as a major factor.

The government might want to rethink how it allocates its educational resources on smoking.”

The results come from a study of over 20,000 men before and after their time in the Israeli military.

Researchers found that 28% smoked one or more cigarettes per day, while 68% never smoked — the remainder were ex-smokers.

Professor Weiser said:

“People on the lower end of the average IQ tend to display poorer overall decision-making skills when it comes to their health.

Schoolchildren who have been found to have a lower IQ can be considered at risk to begin the habit, and can be targeted with special education and therapy to prevent them from starting or to break the habit after it sets in.”

Similarly poor nutrition, problems with narcotics and obesity are also linked to low IQ, Professor Weiser said:

“People with lower IQs are not only prone to addictions such as smoking.

These same people are more likely to have obesity, nutrition and narcotics issues.

Our study adds to the evidence of this growing body of research, and it may help parents and health professionals help at-risk young people make better choices.”

The study was published in the journal Addiction (Weiser et al., 2010).

Eating this meal linked to 5 more IQ points.

Eating breakfast can increase people’s IQ, research finds.

Children who have breakfast on an almost daily basis score better on IQ tests.

Children in the study who ate breakfast had an average of 5 IQ points more than those that did not.

Breakfast provides fuel for the brain after a night of fasting.

Social interaction at breakfast may also help the cognitive development of children.

Dr Jianghong-Liu, the study’s first author, said:

“Childhood is a critical period in which dietary and lifestyle patterns are initiated, and these habits can have important immediate and long-term implications.

Breakfast habits appear to be no exception, and irregular breakfast eating has already been associated with a number of unhealthy behaviors, such as smoking, frequent alcohol use, and infrequent exercise.”

The conclusions come from a study of 1,269 Chinese children.

The results showed that those having breakfast scored 6 points higher on verbal tests and 5 points higher on overall IQ.

Dr Liu continued:

“Because adequate nutrition in early childhood has been linked to increased IQ through childhood, which is related to decreased childhood behavioral disorders, better career satisfaction, and socioeconomic success in adults, breakfast consumption could ultimately benefit long-term physical and mental health outcomes as well a quality of life.

These findings may reflect nutritional as well as social benefits of breakfast consumption on children and hold important public health implications regarding regular breakfast consumption in early young children.

The study was published in the journal Early Human Development (Liu et al., 2013).