Massive Study Reveals If Eldest Children Are More Intelligent — And If It Matters

Are eldest children more intelligent with ‘better’ personalities? Massive study settles this sibling rivalry.

Are eldest children more intelligent with ‘better’ personalities? Massive study settles this sibling rivalry.

Eldest siblings are more intelligent, a new study of 377,000 high school students finds.

However, the difference is equal to, on average, just one IQ point.

This difference is so small as to be almost meaningless.

There were also consistent differences in personality.

Eldest siblings tended to be more outgoing, conscientious and agreeable, while being less anxious.

But, again, these differences were very small.

Professor Brent Roberts, who led the study, explained how small the differences were:

“In some cases, if a drug saves 10 out of 10,000 lives, for example, small effects can be profound.

But in terms of personality traits and how you rate them, a 0.02 correlation doesn’t get you anything of note.

You are not going to be able to see it with the naked eye.

You’re not going to be able to sit two people down next to each other and see the differences between them.

It’s not noticeable by anybody.”

The study controlled for factors like economic status and the number of children.

Professor Rodica Damian, who co-authored the study, said:

“The message of this study is that birth order probably should not influence your parenting, because it’s not meaningfully related to your kid’s personality or IQ,”

The research was published in the Journal of Research in Personality (Damian & Roberts, 2015).

Siblings image from Shutterstock

Breastfeeding Benefits: Higher Adult IQ and Income 30 Years Later

Breastfeeding benefits likely result from long-chain saturated fatty acids in mother’s milk.

Breastfeeding benefits likely result from long-chain saturated fatty acids in mother’s milk.

More infant breastfeeding is linked to higher intelligence, a longer period in education and greater earnings 30 years later, a new study finds.

Dr Bernardo Lessa Horta, who led the study, said:

“The effect of breastfeeding on brain development and child intelligence is well established, but whether these effects persist into adulthood is less clear.

Our study provides the first evidence that prolonged breastfeeding not only increases intelligence until at least the age of 30 years but also has an impact both at an individual and societal level by improving educational attainment and earning ability.

What is unique about this study is the fact that, in the population we studied, breastfeeding was not more common among highly educated, high-income women, but was evenly distributed by social class.

Previous studies from developed countries have been criticized for failing to disentangle the effect of breastfeeding from that of socioeconomic advantage, but our work addresses this issue for the first time.”

Breastfeeding benefits

The study of breastfeeding benefits followed almost 6,000 infants in Brazil from 1982.

They were placed into one of five groups depending on how often they were breastfed.

At the same time the researchers controlled for other factors that might affect IQ, like family income, maternal smoking and genetics.

The researchers found that infants who were breastfed for a year scored, on average, 4 IQ points higher than those who were breastfed for less than a month.

Breastfed infants also went on to spend one more year in education, on average, and earn one-third of the average national income more.

Dr Horta said:

“The likely mechanism underlying the beneficial effects of breast milk on intelligence is the presence of long-chain saturated fatty acids (DHAs) found in breast milk, which are essential for brain development.

Our finding that predominant breastfeeding is positively related to IQ in adulthood also suggests that the amount of milk consumed plays a role.”

The study is published in the journal The Lancet Global Health (Victora et al., 2015)

Breastfeeding image from Shutterstock

8 Household Items Newly Found to Lower Children’s IQ Significantly

Chemicals that may cause a drop in children’s IQ are in products all around our houses.

Chemicals that may cause a drop in children’s IQ are in products all around our houses.

Children exposed prenatally to high levels of phthalates — commonly used in plastics and scented products — have IQ levels seven points lower than those exposed to low levels, a new study finds.

The study is the first to find a connection between phthalate exposure during pregnancy and reduced IQ in children.

The 328 women and their children in the study were from low-income communities in New York City.

Researchers at Columbia University’s Mailman School of Public Health measured levels of four common phthalates, including di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP), during pregnancy (Factor-Litvak et al., 2014).

The children were given an IQ test at 7-years-old.

The results, published in the journal PLoS ONE, showed that children who were in the top 25% for exposure to two particular phthalates (DnBP and DiBP) had IQs around 7 points lower than those who were in the bottom 25% for exposure.

Professor Robin Whyatt, one of the study’s senior authors, said:

“The magnitude of these IQ differences is troubling.

A six- or seven-point decline in IQ may have substantial consequences for academic achievement and occupational potential.”

The researchers controlled statistically for other factors that influence children’s IQ, such as maternal IQ and education as well as the home environment.

Avoiding phthalates

While it is impossible to avoid phthalates completely, they are found in these common products, amongst others:

  • Hairspray.
  • Plastic containers used for microwaving food.
  • Lipstick.
  • Air fresheners.
  • Dryer sheets.
  • Nail polish.
  • Some soaps.
  • Recycled plastics labelled 3,6 or 7.

Dr. Pam Factor-Litvak, who led the study, said:

“Pregnant women across the United States are exposed to phthalates almost daily, many at levels similar to those that we found were associated with substantial reductions in the IQ of children.

While there has been some regulation to ban phthalates from toys of young children, there is no legislation governing exposure during pregnancy, which is likely the most sensitive period for brain development.

Indeed, phthalates are not required to be on product labeling.”

The Best Look for a Leader: Intelligent or Healthy?

What’s the best look for a leader?

What’s the best look for a leader?

When choosing a leader, people prefer a healthy complexion, but mostly ignore the appearance of intelligence, a new study finds.

The findings are based on a Dutch-led study, which looked at the unconscious influence of facial appearance on which leaders people choose for different sorts of leadership (Spisak et al., 2014).

Facial traits can provide all sorts of information about someone’s personality.

For example, a more feminine face — in both men and women — is linked to greater ‘feminine’ qualities, like cooperation.

More masculine faces, however, suggest higher levels of risk-taking.

Participants in the study were shown pictures of the same man digitally adjusted to look more or less intelligent and more or less healthy.

They had to choose the man who would do the best job as CEO of a company which different groups of participants were told had different priorities, such as aggressive competition or moving into new markets.

The results showed that over two-thirds of the time people chose the man with the healthier complexion and this was easily the more powerful influence.

Dr. Brian Spisak, who led the study, said:

“Here we show that it always pays for aspiring leaders to look healthy, which explains why politicians and executives often put great effort, time, and money in their appearance.

If you want to be chosen for a leadership position, looking intelligent is an optional extra under context-specific situations whereas the appearance of health appears to be important in a more context-general way across a variety of situations.”

The only situations in which an intelligent appearance in a leader had an effect was if the position required diplomacy or inventiveness — but it was still a healthy complexion that held sway overall.

The authors conclude that…

“…the activation of “disease concerns” in the environment exacerbates the voting tendency to prefer attractive political candidates.

Attractiveness is in part driven by cues to health and healthy leaders are likely to be exceptionally important when disease threatens the viability of the group.”

Image credit: Roger Braunstein

High Emotional Intelligence Dramatically Improves Decision-Making

High emotional intelligence is about knowing which emotions are relevant.

High emotional intelligence is about knowing which emotions are relevant.

A new study finds that people with high emotional intelligence make smarter decisions because they aren’t swayed by their current emotional state.

The emotions can provide very useful information, but sometimes they are not related to the decisions we are trying to make.

Being able to tell one from the other is part of what constitutes emotional intelligence.

Stéphane Côté, the co-author of a new article published in Psychological Science explained:

“People are driving and it’s frustrating. They get to work and the emotions they felt in their car influences what they do in their offices. Or they invest money based on emotions that stem from things unrelated to their investments.”

Yip and Côté (2013) ran two experiments to test how different people deal with spurious emotional states that are not related to the decision at hand.

In one, participants were made to feel anxious by being asked to prepare an impromptu speech. Then they were asked whether they wanted to sign up to a flu clinic.

The results showed that people with higher emotional intelligence were more aware that the experimentally-induced anxiety they felt was not related to the decision about the flu clinic.

While only 7% of those of low emotional intelligence signed up for the flu clinic, fully 66% of those with higher emotional intelligence did so.

This was in comparison to around a 50% take-up rate for the flu clinic in both groups who hadn’t been made anxious.

A second experiment confirmed these findings.

Crucially, great decision-making is not about eliminating all emotions: they are a vital source of information.

Those with high levels of emotional intelligence are more likely to ignore those emotions that have nothing to do with their decision.

For those who find it problematic making sense of their emotions, the easiest solution is simply stated (although not always easy to execute): wait until later.

Image credit: Saad Faruque

10 Smart Studies that Help Unlock the Mysteries of Intelligence

Reveals the links between intelligence and sleep, mental illness, politics, atheism, happiness and more…

Reveals the links between intelligence and sleep, mental illness, politics, atheism, happiness and more…

The benefits of being smart are hardly a mystery.

Clever people have all kinds of advantages in life: they have better educations, better jobs, earn more and even live longer.

Naturally, then, if you could set your child’s intelligence, you’d probably opt for smart (although maybe not too smart).

Still, being smart is more of a mixed blessing than many imagine.

Here are ten studies that provide vital insights into the psychology of intelligence.

1. The myth of a single intelligence

Some have argued that the idea of intelligence as a single thing is a myth.

According to a recent study of over 100,000 participants, IQ is actually made up of three components (Hampshire et al., 2012).

Analysing the results, they found that IQ split up into short-term memory, reasoning and a verbal component.

In other words: some people could have strong short-term memories but be poor reasoners. Or: some people could be good with language but have poor short-term memory.

Your overall intelligence is a result of how these three subsystems work–and they might not all be at the same level.

2. Intelligence linked to mental illness

Being intelligent isn’t all gravy.

Studies now suggest a link between intelligence and mental illness that may go back into our evolutionary past.

The increased intelligence of Homo sapiens was originally a result of gene mutations. The cost of these gene mutations, however, may have been an increase in mental illness (Nithianantharajah et al., 2012).

The human brain may be the most advanced and complicated object in the universe, but some people pay a heavy price for this gift.

3. Smarts can transcend poor start in life

It’s well-known that being smart helps you get ahead, but what about if you’re smart and disadvantaged? Will your background keep you from achieving?

A study of 12,868 Americans found that while a better background helped people start off with a better job, it was smarts that helped them progress from there (Ganzach, 2011).

Yoav Ganzach explained:

“Your family can help you launch your career and you do get an advantage, but it doesn’t help you progress. And once you start working, you can go wherever your abilities take you.”

4. Clever but worried

They say that ignorance is bliss, and ‘they’ may well be on to something.

That’s because people of high intelligence are more prone to anxiety than those of moderate intelligence.

Indeed, anxiety may have co-evolved with intelligence–worrying may have given early humans a survival benefit in the ancient past (Coplan et al., 2012).

It’s just a pity that it’s left intelligent people with higher levels of anxiety disorders.

5. New ideas

Set against the higher levels of mental illness and anxiety, is the fact that more intelligent people are more likely to come up with new ideas.

Historically, that might mean rejecting superstition and finding new ways of organising society.

One study argues that this explains why more intelligent people are more likely to be atheists and more likely to be politically liberal (Kanazawa et al., 2010).

This study found that young adults who described themselves as ‘very conservative’ had an average IQ of 95, while those who described themselves as ‘very liberal’ had an average IQ of 106.

6. Motivation can trump IQ

Although intelligence can be a wonderful asset to have, it doesn’t guarantee success.

Take maths, that bastion of nerd achievement. It’s true that being intelligent will give you a good start, but for real achievement you’ve got to be motivated.

A German study of 3,520 children found that after they got started at maths, their intelligence became less important than their motivation to succeed and how much they studied (Murayama et al., 2012).

7. Intelligence is in the eyes

Literally, that is.

A study by Shalev et al. (2013) has found that people who have wider blood vessels at back of the eye have higher levels of intelligence.

This is because retinal blood vessels are similar to those in the brain. So, wider blood vessels here may mean a better supply of oxygen to the brain.

This finding could even be important in diagnosing and treating brain diseases:

“Increasing knowledge about retinal vessels may enable scientists to develop better diagnosis and treatments to increase the levels of oxygen into the brain and by that, to prevent age-related worsening of cognitive abilities.” Shalev et al. (2013)

8. The intelligent sleep later

This is no longer a feeble excuse for hitting snooze.

Evidence has now been published that people who are more intelligent tend to go to bed later and get up later (Kanazawa & Perina, 2009).

The study examined the sleep habits of 20,745 adolescent Americans and found that on a weekday the ‘very dull’ went to bed at an average of 11:41 and woke up at 7:20.

In contrast, the ‘very bright’ went to bed at 12:29 and got up at 7:52. At the weekend the differences were even more pronounced.

We don’t know the nature of the connection from this study, but perhaps bright people find it more difficult to get to sleep because of all the worrying they’re doing.

9. Are smart people less racist?

Well, smart people certainly sound less racist. They know what they are supposed to think and say.

But, when they are tested on actual political policies, their views turn out not to be as enlightened as they might like.

These findings are based on a study by Geoffrey Wodtke, who explained:

“…although nearly all whites with advanced cognitive abilities say that ‘whites have no right to segregate their neighborhoods,’ nearly half of this group remains content to allow prejudicial real estate practices to continue unencumbered by open housing laws.”

So it seems smart people are better at concealing their views.

10. Smarter societies are happier

Are smarter people happier? Overall, probably not.

Studies which have looked for a connection between how happy people feel and how intelligent they are have mostly found no connection (e.g. Veenhoven & Choi, 2012).

However, when you look across nations, those that are, on average, smarter, are also happier.

So being smart might not benefit people’s happiness individually, but it may help contribute to everyone’s happiness.

Image credit: Kris Kesiak

Daryl Atkins’ Fate Hanging On His IQ

Daryl Atkins

“The life of a convicted murderer is hanging in the balance while a US jury considers whether his intelligence has increased enough to allow him to be put to death.

…the intellectual stimulation the killer got by constant contact with lawyers in the case is thought to have raised his IQ above the threshold of 70, which puts him in line for the death penalty in Virginia.”

Incredible that anyone’s life could rest on an outmoded measure like IQ.
BBC News
Washington Post

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