IQ heritability

Twins and IQ heritability
Twins are a good starting point in the evaluation of IQ heritability

I have previously written about IQ heritability. It is the age old question of nature versus nurture. There are a reasonably large number of studies which examines IQ heritability. While the existing body of literature refutes anti-genetics ideology, it also lends support to environmental effects as well. So the extant body of literature of IQ heritability also suggests that the environment plays an important part in explaining some of the IQ variances observed between groups. The most interesting studies that currently exist are kinship and adoptive studies. For example some of the kinship studies look at fraternal vs. identical twins, which represent a great starting point to establish IQ heritability, namely how differences in IQ scores may be explained by genetic and/or environmental factors. This is so because it is not unreasonable to assume that fraternal twins (who are born together, but share only 50% of genes – the same as any normal siblings) are likely to benefit from the same environment as they grow up. On this basis, comparing the variability of fraternal twins IQ scores with identical twins (who share 100% of the same genes) reveals important and undeniable evidence in respect of the debate. These studies have shown that 50% of IQ is likely to be heritable, and initial studies from the late 1970s have been confirmed over the last few decades.

IQ heritability: what the existing literature says.

Adoption studies are also particularly interesting in assessing IQ heritability. That is, if environment/nurture is a leading explanatory variable for the variability in IQ scores, then one would expect that adoptive children’s IQs should converge towards the performance of any siblings residing in their adoptive households, including any genetic children of the adoptive parents or the adoptive parents themselves. The Texan adoptive study for instance, found that at age 8, the correlation between IQ scores between the child and adoptive parents was 0.13, compared to 0.32 as compared to their genetic mothers. When the children were re-tested by the age of 18, the IQ correlation coefficient with adoptive mothers and fathers had fallen to 0.02 and 0.10 respectively, while IQ correlation coefficients with biological mothers has increased to 0.48.  The conclusions here are that genetics prevail over the long run, giving credence to the notion of IQ heritability.

I will write further on this topic in my next posting.

For more information on IQ and to test your IQ online, you can click here or visit www.iq-brain.com

Higher IQ in apes

Higher IQ in apes
Higher IQ in apes: is the cerebellum more important than previously thought?

A new study by researchers at Durham University in the UK looks at the evolution of the brain of primates relative to other monkeys. The lead researcher suggests that the prior thinking about the evolution of apes’ brains may have been wrong. That is, scientists were focusing too much on the neocortex, which is the folded outer part of the brain which makes human brains particularly distinct. The researchers found that early monkeys’ brains may have experienced simultaneous growth in the neocortex and the cerebellum. But this may have changed 25 million years ago, when apes suddenly experienced accelerated growth in the cerebellum compared to growth in the neocortex. This could well have propelled higher IQ in apes relative to other species of primates.

There are several theories as to why this may be the case. Some scientists have posited that the sudden acquisition of technical abilities have have triggered the supernormal growth of the cerebellum. The cerebellum of an ape contains significantly more neurons than the cerebellum of a monkey, even when the monkey’s brain is scaled to match the size of an ape. In fact, it is reported that apes have on average 16 billion more neurons than monkeys. This figure equates to the entire amount of neurons contained in the cerebellum of a human brain.

So higher IQ in apes may have been the result of acquiring new technical skills such as swinging from trees, and eventually the ability to even learn how to use tools in hunter / gathering activities.

Higher IQ in apes: cerebellum or neocortex?

But the neocortex and the cerebellum work together. As the brain’s cerebellum might have expended as a result of acquiring new activities, the neocortex would have needed to expand and play catch up in order to be able to synthesize information, reactions and reflexes.

There are potentially parallels to be drawn from humans. Higher IQ in apes, acquired out of developing new skills, is not dissimilar to higher IQs in humans (and their offspring) who have higher levels of education and more intellectually challenging professional jobs. In humans, it is estimated that 60% of IQ is heritable, while the rest is environmental. Heritability is a key trait of IQ, and it would be interesting to understand whether humans have also experienced continued growth in their cerebellums since the industrial revolution, or whether the growth in the neocortex and cerebellum occurred in tandem.

But whether cerebellum or neocortex led, higher IQ in apes seems to have been the result of acquiring new skills (a form of education).

To test your IQ, click here.

Famous high IQ people which you might not expect

High IQ people that may surprise you
High IQ people that may surprise you

IQ stands for ‘Intelligence Quotient’ and is a score which attempts to characterize people’s intellectual ability. IQ scores reflect the measurement of intelligence via the administration of a standardized IQ test deriving from great IQ researchers such as Cattell, Weschler or Otis. The science behind IQ testing is sound.  IQ testing has been around for over 100 years and many of the well-known IQ tests have been administered to millions of people across the globe. This large number of test observations has allowed scientists to establish that intellectual ability, as proxied by standardized IQ scores, is normally distributed. This means that  IQ scores follow a bell curve, which is able to be derived with the knowledge of two variables: mean and standard deviation. The mean or the average, is usually set to 100. In other words, IQ developers tell us that IQ scores are normally distributed around an average score of 100. Based on the shape of the bell curve, we know that 50% of the population will have an IQ score which is greater than 100, while the other 50% of the population will have an IQ score which is lower than 100. The standard deviation is the dispersion of results around the mean score. And conveniently, statistical properties can help us establish precisely what percentage of the population is expected to have an IQ score between a particular range. The most typical standard deviations on IQ tests are 15, 16 or 24 points. Very high IQ people are those with an IQ score which is in excess of two standard deviations of the mean.

Famous high IQ people: where to look for their IQ scores?

There is a lot of speculation about famous high IQ people on the Internet. Or put differently, some of us are very curious as to what the IQ of famous people may be. For instance, some of us might have searched for “Barack Obama IQ” or “Bill Gates IQ” on a search engine. Search engine results are various but the real problem with these searches is that IQ is a private matter and few people may be willing to publicly reveal their scores, if these are even known by the individual in question. Not everyone has taken a standardized IQ test, and there is further considerable downside for famous people to share their IQ scores, although famous high IQ people may be less reluctant to share their score, particularly if the score in question is impressive. So the vast majority of search engine results purporting to have an answer about the IQ of specific individuals are usually bogus or may represent the product of inference or guess work.

Enter high IQ societies. Mensa is a high IQ society which is open to membership to anyone who has an IQ score in the 98th percentile of the population, or the top 2%. This corresponds to an IQ score of 130+ (15 standard deviation), 132 (16 SD) or 148 (24 SD). So Mensa members, also known as Mensans are high IQ people.

So if someone famous has an IQ in the 98th percentile of the population, that person is eligible for Mensa membership. There is quite a long list of famous high IQ people who appear on the roster of high IQ societies such as Mensa.

Famous high IQ people who you never would have guessed…

1. Asia Carrera: that’s right, the former porn start actress is a Mensan and reported to have an IQ of 156. She also had a scholarship to attend Rutgers University but never graduated. I can’t see that the lack of a college degree stopped her from achieving success, at least in the line of work that she chose.

2. Geena Davis: having starred in The Fly and Beetlejuice is another Mensan who graduated from Boston University with a degree in drama. Who says artsy fartsy types aren’t smart?!

3. Alfred George Hinds was a career British criminal who was locked away for 12 years after being arrested on a robbery charge. Hinds became known as the Houdini of the criminal world as he successfully broke out of three high security prisons and would eventually secure a pardon from the state using his knowledge of the law. The proceeds of his robberies were never recovered.

Famous people with high intelligence may not necessarily want to reveal their IQ scores to the public. But Mensa membership is enough to identify some of the brightest out there.

You could be the next bright spark to become a Mensa member. To test whether you have qualifying IQ, click here or visit www.iq-brain.com – for more information about people high IQ people.

Does IQ matter? (part II)

Does IQ matter?
Does IQ matter? It does when it comes to education and employment prospects

In our last posting, I looked at the question: Does IQ matter? And in particular, I took a fairly basic angle of examining whether having a very low IQ would in fact become a limiting factor in education, employment and economic freedom. What is self evident is that people with very low IQs may struggle with standard life processes such as education, and achieving economic freedom.

Does IQ matter? Evidence from the lower half of the distribution suggests that it does. Very low IQs may be associated with learning difficulties. At the extreme case, people with IQs in the 60s or 70s may not be able to live independent lives and may require long term care. Above 70s and into the low 80s, people may struggle in formal education, which in turn may hinder their ability to gain qualifications which lead to skilled employment, hampering prospects of achieving financial independence. As people’s IQs approach 90, the prospects of getting through high school is significantly enhanced, and a mid 90s IQ even allows some to go on and complete tertiary education, which in turn significantly enhances employment prospects for many. Does IQ matter? The evidence is overwhelming that it does.

What about the right hand tail of the IQ distribution? Well, ‘normal IQ’ is usually associated with a score lying between 90 and 109. This is the category that nearly 50% of the population fall into (47.2% to be precise). People will normal IQs are able to function in the society we will in. People with this level of IQ should be able to finish their high school education and some people within this range are able to successfully complete their university degree. This in turn enhances employment and earnings prospects on the whole, which means greater financial independence. The types of jobs that are available to people in this IQ range include education, sales, public administration, finance and real estate occupations.

Does IQ matter? Let’s look beyond the average.

Does IQ matter for people with above average IQ? Let’s discuss this now.

The next IQ category is high average (IQ between 110 and 119). This is typically the range of IQ of most college or university students. People with high average IQs are able to secure jobs as managers, accounting, high school education, social work and the like.

Within the next IQ category of ‘superior IQ’ (120 to 129) we find individuals that are not only able to successfully graduate from university, but people who have enough raw brain processing power to be able to go on to pursue more professional careers from engineering, medicine to legal occupations. This is the IQ bucket for which mothers can safely tell their children: “the World is your oyster”.

IQ levels over 130 start with the ‘gifted’ category, progressing through to ‘genius’ which means that people with this level of IQ may not only pursue the career of their choice, but they can elevate themselves beyond the status quo and propose and implement changes to the way society operates.

Does IQ matter? Of course it does. It does down to the point, but on average, people with higher IQs are able to get more out of life because most paths are available to them. Ignoring extraordinary genius IQ levels which may lead some individuals to feel isolated, high IQs lower the struggle and friction that people experience when faced with key life hurdles that most of us need to go through: education and employment. The ability of these people to make better choices typically leads to more economic freedom and happiness.

To test your IQ, go to www.iq-brain.com or click here.

Does IQ matter?

Does IQ matter?
Does IQ matter? Well, greater IQ expends your universe of potential careers

Does IQ matter? So many would like to either dismiss or downplay the importance of IQ. Why should anyone place any level of importance of what is appears to be a score on a brain-twister type quiz? The realities about IQ are highly uncomfortable for many: for instance, IQ has been found to be normally distributed, with a mean of 100 and a standard deviation which varies depending on the test taken (standard deviations of 15, 16 or 24 are the most commonly found on well-known IQ tests). What this really means is that half of the population will have an IQ of over 100, while the other half of the population will have an IQ of less than 100. “So what?” one may ask. Well, at the lower extremes, IQs of less than 70 have historically been associated with heavy learning difficulties or mental retardation. Does IQ matter? Clearly, a low IQ may be problematic, and the harsh reality is that 2.6% of the population have an IQ of less than 70 (16 SD). So very low IQs are not all that uncommon.

Putting the issue of lower extreme IQ to one side, IQs between 70-79 are often known as “well below average” or “borderline” IQs. People with IQs in this range may find it difficult to finish high school, and may be drawn into manual labor-heavy professions. At this level of IQ, people can secure positions such as janitor, precision machinery operators and truck drivers.

At IQs of 90-109, people have an ‘average’ level of intellectual activity – 47% of the population have an IQ within this bracket. The bracket in question has a 19 point range within, so there is a substantial difference in intellectual ability between someone who has a 109 IQ as opposed to a 90 IQ. However, people at this level of IQ should be able to get through high school, and some even go on to complete tertiary education with hard work. Even at the 90 IQ mark, people at this level of IQ are typically able to go on and be successful in professions such as carpentry, plumbing and working as a foreman. Towards the higher end of the range, individuals can become successful sales people, policemen or buyers.

Does IQ matter? Evidence from the lower half of the distribution.

So thus far, we’ve only talked about IQs in the average range or below (IQs less than 109). So does IQ matter? What should be apparent is that the higher the IQ, the higher the likelihood of being able to finish high school with relative easy, and at ranges of 90+ people are normally able to go on and complete some level of education, and the range of jobs that are available to people towards the end of the range, is significantly broader than what people may be able to access at the lower end of the IQ range.

The higher the IQ, the more economic freedom individuals are likely to have. This does not necessarily mean that people will be happier, but on the whole, one would also expect this to be the case.

Does IQ matter when IQ is greater than 100? I will discuss this in future postings.

In the meantime, to test your IQ, visit www.iq-brain.com, or click here.

High IQ psychopaths

High IQ psychopaths on Wall Street
Could Wall Street be full of high IQ psychopaths with Factor One psychopathic tendencies?

A recent study by an undergraduate student at the University of Huddersfield has posited that up to 3% of people in senior management positions may be High IQ psychopaths. The study suggested that people who display Factor One psychopathic tendencies  and higher IQs were much more likely to be able to fake their emotional responses in tests that could reveal their personality disorder, giving them free reign to climb the corporate ladder and access senior management positions.

The study started by testing the IQ of 50 students, and via the administration of the Levenson Self-Reported Psychopathy Scale, identified those students which displayed Factor One or Factor Two psychopathic tendencies.

During the study, students were evaluated using a Galvanic Skin Response (GSR) and had electrodes attached to their fingers. They were then shown disturbing images which would cause distress to most people (other than those who demonstrate psychopathic tendencies). The expectation would be for people with Factor One psychopathic tendencies to demonstrate little or no emotional response to the images, while people with Factor Two psychopathic tendencies would be expected to generate higher levels of emotional response due to excitement.

The results of the study were largely in line with expectations, with the exception that it was the study participants with the lowest IQs who were found to demonstrate the highest level of excitement when shown the disturbing images, as opposed to those who might display Factor Two psychopathic tendencies.

The author of the study suggests that people with Factor One psychopathic tendencies, and higher levels of IQ, are more likely to be able to fake emotional responses which might reveal their psychopathic tendencies, which in turn might explain why these types of people may be in found in greater proportions in senior managerial positions.

High IQ psychopaths in Big Business

If it is true that big business may harbor a larger number of high IQ psychopaths, this may explain why many higher performing corporate environments may be seen as being so political and backstabbing.

But the assertion that higher IQ people may also be better at faking emotional responses also suggests emotional intelligence, or at the very least, self awareness and better emotional control. As described on my previous post here, emotional intelligence and IQ are highly correlated and this new study is very simply an extension of this assertion. That is, higher IQ psychopaths are smart enough to know and recognize what they are, and are able to tone down the responses.

So could this mean that Wall Street may be harboring mass numbers of high IQ psychopaths?

To test your IQ, go to www.iq-Brain.com or click here.

Free IQ tests

Free IQ tests
Free IQ tests. Are they worth it?

There are a multiple of Free IQ tests online. But what do you gain by taking them? Are these IQ tests accurate enough to tell the test taker anything about his or her IQ? We examine some of the pitfalls with free IQ testing.

First of all, nothing in life is really free. IQ test developers who go and create an IQ test isn’t investing time and money to do the online web community a public service. There is usually a monetization strategy behind the creation of the site. When the site is free, the monetization strategy is clearly web traffic, which is worth money because this source of traffic can be sold to online web advertizers. So the tests may be free to take by the end user, but this does not mean that the developer is doing this as a public service.

But who cares what the developer makes out of the site? I just really want to find out what my IQ level is you may say. This is all fine and well, but the likelihood is that a free online IQ test will not have had much investment and research behind it, and their accuracy is therefore doubtful. Specifically, we have tested several free online IQ tests and their biggest problem is that (1) they often do not have a time limit, and (2) the results are inflated which leads the test taker to believe that he or she is a Genius. Some users who start with free IQ tests may go on to take a professionally-administered Mensa IQ test only to realize that their real IQ score is significantly lower than what they had achieved online. It is well known that online IQ test may inflate IQ scores by 15-30 points. Taking a test produces inflated test results is meaningless.

Free IQ tests vs paid for IQ tests

Free IQ tests are fun, and a few of them have been reasonably well thought through. That said, paid for IQ tests do not seek to monetize the traffic to generate advertizing revenues. Instead, they survive by having high IQ test results which are more likely to be comparable to what the test user would achieve in a professionally administered IQ test.

This is not to say that all paid-for IQ testing sites are good. In actually, several of them yield over inflated IQ test scores. But these spurious tests are likely to be found out and will not survive. Free IQ tests, on the balance, are inferior to paid for ones.

For a good paid for IQ test, see www.iq-brain.com or www.nicologic.fr

To test your IQ now, click here.

IQ decreases

Fertility rates and IQ
Decreases in IQ globally could be due to fertility rates falling in developed nations

The Flynn Effect was the name given to the fact that several countries had reported findings which suggested that average IQ levels were increasing at a rate of 3 IQ points per decade in the United States. This finding would in fact suggest that Americans were getting smarter at a rate of 8-9 IQ points per generation. Scientists never reached consensus as to why this effect may have been taking place. Several explanations and theories were put worth including better diets and healthcare, the addition of iodine to salt, and the bombardment of information via technology.

But although 3 IQ points per decade sounds large, this is eclipsed by some of the reported Flynn gains in other countries including the Netherlands, Belgium and Canada which experienced gains per decade of between 4-6 points according to some estimates. So for a while, it appeared that people were getting smarter, although this assertion was and is still debated.

A new study has found the opposite and reports that IQs in the UK, Denmark and Australia have declined by 1.5 points since 1998, a finding that suggests the opposite of the Flynn Effect may be happening.  Specifically, an IQ test used in Denmark to establish whether individuals are fit to serve in military has recorded a 1.5 point decline over a 16 year period. The IQ decreases have elicited a raft of responses by scientists.

Although this could well be just a blip, these IQ decreases have caused a strong reaction in the scientific community, with some researchers suggesting that humans have reached an intellectual peak, and therefore that a gradual decline may have begun and that further IQ decreases may be yet to come. The relaxation of education standards may also be behind the trend.

IQ decreases: global vs national data

Richard Lynn from the University of Ulster has used average IQ data from several countries and has calculated that IQs have dropped by 1 point between 1950 and 2000.  If the answer really happens to be that average populations are 1 point dumber than they were 60 years ago, this is nothing to get alarmed about. This level of detail would be largely insignificant.

One interesting explanation for these IQ decreases is that more educated people are having less children, which would mean that the less educated masses would be sustaining population numbers. This is not only entirely plausible but especially relevant when looking at the changes in IQ for the world as a whole given the very low birth rates in industrialized nations relative to developing economies. Several African countries have average IQs in the 70s, compares to high 90s or low 100s for rich nations. The fertility rates in some African countries are >4 while they are less than 2 in may industrialized nations. That said, African and developing countries are likely to experience some level of positive Flynn effect as they develop and begin offering their citizens better education, nutrition and healthcare.

To test your IQ, go to www.IQ-Brain.com and take our three fluid intelligence IQ tests.

Fish consumption can boost gray matter

fish consumption can boost gray matter
New study: fish consumption can boost gray matter

A recent study by the University of Pennsylvania found that regular fish consumption can boost gray matter, brain tissue that is made mostly of brain cells. In other words, fish consumption can boost gray matter and brain health generally. Greater density of gray matter in certain parts of the brain can lead to improved cognitive function generally, and perhaps intelligence. This study illustrates a clear link between brain health and diet and lifestyle, which is an important finding in the context of an ageing population. The takeaway: broiled or baked fish consumption cash boost gray matter; the study made no reference to canned or grilled fish.

The study was based on a previous longitudinal study in which people over the age of 65 were followed over a period of over ten years between 1989 and 1999. It would appear that fish consumption can boost gray matter  (as measured with MRI scans) in two areas of the brain. The study found that people who consumed fish on a regular basis has 4.3% more gray matter in their frontal lobes than those who did not consume fish regularly. Frontal lobes are typically associated with planning and higher cognitive functions. Similarly, the high fish consumption cohort had 14% more gray matter in the areas of the brain associated with memory. Interestingly, the authors noted that the gray matter differentials were linked to actual fish consumption as opposed to omega-3 fatty acids. This latter finding is surprising, although the lead author of the study notes that pursuing greater consumption of omega-3 fatty acids naturally is basically the same as consuming more fish.

Importantly, the study took into account several factors that are believed to be implicated with gray matter, and the overall conclusion remained robust after controlling for these factors.

Fish consumption can boost gray matter: so what?

There are several implications here. Firstly, it would appear that fish consumption may be directly related to our brain health as we get older. Preserving cognitive function and memory are key to leading more independent lives as we live into old age. It also occurs to me that such a simple change in lifestyle (e.g. eating fish twice weekly) should be a matter of public policy, particularly in countries with universal healthcare systems.

What is disappointing with this study is that there was no direct evaluation of IQ between cohorts.

In any case, I know what I am eating this evening.

To test your IQ, click here (www.iq-Brain.com).

 

 

Cannabis lowers IQ

Cannabis lowers IQ
Cannabis lowers IQ by up to 4 points

Several studies have previously argued that cannabis lowers IQ levels. For instance, a large New Zealand study of 1,000 individuals measured the IQs of participants at the age of 13, and again at 38, while assessing pot smoking habits in the interim period. The study found that individuals who had reached the age of 18 and had become addicted to cannabis experienced a drop in their IQ scores when measured again at the age of 38. According to this study, it does appear that cannabis lowers IQ.

Although this study has been criticized as it did not control for other life choices during the two IQ testing periods, it has corroborated previous studies find also speculated that cannabis lowers IQ.

A new Canadian study also examined whether cannabis lower IQ. The eight year study followed 70 teenagers, who had their IQ tested at the age of 12 and again between the ages of 17 and 20. The study found that teenagers who smoked more than five joints per week experienced an average IQ drop of 4 points. Although this may not sound like a big drop, it’s important to be reminded that 50% of the population have IQs of less than 100. So losing four points will not provide do anyone any favors.

Cannabis lowers IQ, but also increases the chances of developing a mental illness

The message is clear: Cannabis lowers IQ. And this body of research comes on the heels of other scientific investigations including a study of 2,000 teenagers which demonstrated that teenagers who have smoked marijuana more than 5 times were twice as likely to experience psychosis in the following 10 years as those who did not use cannabis. In turn, people who experience psychosis are more likely to go on and develop schizophrenia.

Schizophrenics are also well known to experience substantial drops in IQ throughout their lifetime.

What is clear is that cannabis lowers IQ, but it also increases the chances of developing mental illnesses which have also been shown to lower IQ. When it comes to the brain and smarts, cannabis is not friend.

You can test your fluid intelligence here at www.IQ-Brain.com.