How much of our intelligence is inherited?

Posted on August 6, 2024August 13, 2024 by Itamar

The origins of human intelligence have puzzled scientists and philosophers for centuries. This complex trait, encompassing our ability to learn, reason, and comprehend, is crucial in shaping individual success and societal advancement. Understanding the relative contributions of genetics and environment to intelligence has profound implications for education, policy-making, and our perception of human potential.

Genetic Influence on Intelligence

Research has consistently shown that intelligence is one of humans’ most heritable behavioural traits. Heritability estimates for intelligence follow a distinctive pattern, increasing from roughly 20% in infancy to 80% in adulthood. This trend indicates that while environmental factors significantly impact early cognitive development, genetic influences become more prominent with age.

Several factors may explain the increasing heritability of intelligence over time. Individuals gain more autonomy in shaping their environments to align with their genetic predispositions as they mature. The cumulative effects of minor genetic influences may also become more apparent as time progresses.

Recent advancements in genetic research, particularly Genome-Wide Association Studies (GWAS), have shed light on specific genetic variants associated with intelligence. These studies have identified numerous genetic loci that account for approximately 20% of intelligence heritability. This progress highlights the “missing heritability” concept – the gap between the high overall heritability of intelligence and the fraction explained by currently identified genetic variants.

Researchers continue to investigate the missing heritability, exploring possibilities such as rare genetic variants with significant effects, complex interactions between multiple genes, and epigenetic factors influencing gene expression without altering DNA sequences.

Mechanisms of Genetic Influence

Genetic influence on intelligence operates through several mechanisms. Assortative mating, where individuals tend to choose partners with similar traits, shapes the genetic landscape of intelligence. Studies have revealed higher spouse correlations for intelligence compared to many other characteristics. This tendency for intelligent individuals to pair up and reproduce can increase the genetic variance for intelligence in populations over generations.

Recent research has uncovered intriguing aspects of genetic influence on intelligence, including the potential role of conditioned genes. Some studies suggest that specific genes associated with advanced cognitive functions may only be activated when inherited from the mother. This finding underscores the intricate nature of genetic inheritance and highlights the potential significance of maternal genetic contributions to intelligence.

Environmental Factors

While genetic factors substantially influence intelligence, environmental influences are critical, especially in early life. Environmental factors are estimated to account for about 50% of the differences in intelligence among individuals during childhood and adolescence.

These environmental influences include education quality, nutrition, socioeconomic status, and early childhood experiences. The availability and quality of educational opportunities can significantly impact cognitive development and intellectual achievement. Adequate food, particularly during early childhood, is essential for optimal brain development and cognitive function.

The influence of the environment on intelligence is particularly evident in the impact of maternal care and support. Emotional solid bonds and intellectual stimulation mothers provide have been shown to affect a child’s cognitive development significantly. This maternal influence operates through genetic and environmental pathways, highlighting the complex interplay between nature and nurture.

Interaction Between Genes and Environment

The dynamic interaction between genetic predispositions and environmental factors is perhaps the most fascinating aspect of intelligence inheritance. This interplay is exemplified by gene-environment correlations, where individuals with specific genetic propensities seek out or create environments that match and reinforce those tendencies.

For example, a child with a genetic inclination towards verbal ability might show more interest in reading, prompting parents and teachers to provide additional opportunities for language development. Over time, this process can amplify the effects of genetic predispositions, contributing to the increasing heritability of intelligence with age.

The malleability of intelligence in response to environmental factors opens up possibilities for interventions. Various programs and strategies, such as early childhood education initiatives, cognitive training, and nutritional supplementation, have shown promise in enhancing cognitive abilities, particularly in children from disadvantaged backgrounds.

Expanding our Understanding

As research in this field progresses, we will likely gain even deeper insights into the genetic and environmental factors contributing to intelligence. These advances open new possibilities for personalized education and interventions to optimize cognitive development.

Future research directions may include:

Epigenetic studies: Investigating how environmental factors influence gene expression without altering DNA sequences, potentially explaining some of the missing heritability.
Longitudinal studies: Tracking individuals from early childhood through adulthood to better understand how genetic and environmental factors interact over time to shape intelligence.
Cross-cultural comparisons: Examining how genetic and environmental influences on intelligence may vary across different cultures and societies.
Neuroimaging studies: Using advanced brain imaging techniques to explore the neural correlates of intelligence and how they relate to genetic and environmental factors.
Gene-environment interaction studies: Investigating how specific genetic variants may respond differently to various environmental influences.
Developmental trajectory analysis: This study examines how the relative contributions of genetic and environmental factors change throughout different stages of life.
Intervention studies: Developing and testing targeted interventions based on genetic and environmental risk factors to enhance cognitive development.
Twin and adoption studies: Using these robust research designs to disentangle genetic and environmental influences on intelligence.
Molecular genetic studies: Identifying additional genetic variants associated with intelligence and exploring their functional roles in cognitive processes.
Computational modelling: Developing sophisticated models to simulate the complex interactions between genes and environment in shaping intelligence.

Ethical Considerations

As we uncover more about the genetic basis of intelligence, it is crucial to approach these findings with care and consideration. The ethical implications of genetic research on intelligence are profound and require thoughtful discussion to ensure that this knowledge is used responsibly and equitably.

Some vital ethical considerations include:

Avoiding genetic determinism: Recognizing that genetic influences do not predestine individuals to specific levels of intelligence.
Preventing discrimination: Ensuring that genetic information related to intelligence is not used to discriminate against individuals in education, employment, or other areas of life.
Addressing inequalities: Using our understanding of genetic and environmental influences to develop strategies that reduce disparities in cognitive development and educational outcomes.
Respecting individual privacy: Safeguarding genetic information and ensuring individuals control how their genetic data is used and shared.
Promoting equity in research: Ensuring that genetic studies of intelligence include diverse populations to avoid biases and improve the generalizability of findings.
Fostering public understanding: Educating the public about the complex nature of intelligence inheritance to prevent misinterpretation and misuse of genetic information.
Considering societal implications: Reflecting on how advances in our understanding of intelligence inheritance might impact social policies, educational practices, and cultural values.

In conclusion, while a significant portion of our intelligence is indeed inherited, the story of human cognitive ability is an ongoing interaction between our genetic heritage and our lived experiences. This understanding enriches our scientific knowledge and empowers us to create environments and opportunities that allow all individuals to reach their full cognitive potential.

Exploring the Wechsler Adult Intelligence Scale (WAIS)

Posted on March 25, 2024July 24, 2024 by Itamar

The Wechsler Adult Intelligence Scale (WAIS): A Cornerstone of Cognitive Assessment

The Wechsler Adult Intelligence Scale (WAIS) is a fundamental instrument in assessing human cognitive abilities. Developed by David Wechsler in 1955, it has undergone multiple revisions to maintain its relevance and accuracy in measuring adult intelligence.

Structure and Domains of the WAIS

The WAIS evaluates individuals between 16 and 90 years old across four primary cognitive domains:

Verbal Comprehension
Perceptual Reasoning
Working Memory
Processing Speed

These domains collectively provide a comprehensive profile of an individual’s intellectual capabilities.

Test Components and Scoring

The test consists of various subtests designed to measure specific cognitive skills. For example, the Vocabulary subtest assesses language development and word knowledge, while the Block Design subtest evaluates visual-spatial reasoning and problem-solving abilities.

One of the strengths of WAIS lies in its ability to generate both an overall intelligence quotient (IQ) score and separate scores for each cognitive domain. This multifaceted approach allows a nuanced understanding of an individual’s cognitive strengths and weaknesses.

Applications of the WAIS

The WAIS has found applications in numerous fields:

Clinical Psychology: It aids in diagnosing cognitive impairments and intellectual disabilities.
Educational Settings: The test helps identify learning disabilities and inform educational planning.
Neuropsychology: It assists in assessing cognitive functioning following brain injuries or neurological conditions.
Research: The WAIS serves as a standardized measure of intelligence in various studies.

The Rise of Online Cognitive Assessments

The advent of online cognitive assessments has led to digital versions of IQ tests, including those based on the WAIS framework. These online tests offer increased accessibility and convenience. Users can take the test from their homes, often receiving instant results.

Limitations of Online WAIS-Inspired Tests

However, online WAIS-inspired tests come with significant limitations:

Lack of Professional Administration: The WAIS is designed to be administered by trained professionals who can observe and interpret behaviour during the test.
Absence of Controlled Environment: Online tests cannot replicate the standardized testing conditions of an in-person assessment.
Limited Validity: Without proper validation studies, the accuracy of online versions remains questionable.
Incomplete Assessment: Many online tests focus solely on IQ scores, neglecting the comprehensive cognitive profile provided by the full WAIS.
Potential for Misinterpretation: Individuals may need professional guidance to understand their test results.

For these reasons, online WAIS-inspired tests should be approached with caution. They may serve as entertaining exercises or provide a rough estimate of cognitive abilities, but they cannot replace a professionally administered WAIS in clinical or educational settings.

The Future of Intelligence Assessment

The future of intelligence assessment likely involves a blend of traditional methods and technological advancements. Researchers are exploring ways to leverage artificial intelligence and machine learning to enhance cognitive testing. These technologies could potentially:

Adapt test difficulty in real-time based on performance
Analyze subtle behavioral cues during test-taking
Provide more accurate and culturally fair assessments

Emerging Technologies in Cognitive Testing

Virtual reality (VR) and augmented reality (AR) technologies may also be used in future cognitive assessments. These immersive environments could offer more engaging and ecologically valid testing scenarios.

Enduring Principles of the WAIS

Despite technological advancements, the core principles of the WAIS remain relevant. The test’s emphasis on multiple cognitive domains and its standardized administration continue to provide valuable insights into human intelligence.

Evolving Concepts of Intelligence

As research in cognitive science and neuroscience progresses, our understanding of intelligence continues to evolve. Howard Gardner’s concept of multiple intelligences challenges the notion of a single, unified intelligence measured by traditional IQ tests.

This evolving understanding may lead to future revisions of the WAIS or the development of new assessment tools that capture a broader range of cognitive abilities. These include measures of emotional intelligence, creative thinking, or practical problem-solving skills.

The WAIS and its online derivatives represent a continuing effort to quantify and understand human cognitive abilities. While online tests offer increased accessibility, they cannot replace the depth and accuracy of professionally administered assessments.

As technology advances and our understanding of intelligence deepens, cognitive assessment tools will likely become more sophisticated and comprehensive. The challenge lies in balancing technological innovation with the rigorous standards and professional interpretation that have made the WAIS a trusted instrument in psychological assessment.

Ready to embark on the journey of intelligence assessment?

Click here to begin the WW IQ TEST now!

Top 10 Brain Training Apps

Posted on November 27, 2020June 26, 2024 by Itamar

Performance is the main reason for pressure and stress in today’s high-paced world. We are
constantly on the spotlight when it comes to getting whichever task done as quickly and efficiently
as possible that we often forget to take care of ourselves. We are always on the clock and this takes
a huge toll on our overall health and energy levels.
This is not something you should worry too much about though. There is no need to think you are
going crazy, let alone to start knocking on your friendly neighborhood therapist’s door. All you need
is a little motivation. The following list will run you through 10 great apps to help you keep the juices
flowing and your mental health as sharp as ever.

1. Lumosity
Lumosity is one of the most respected, well known and consolidated brain training and mental
fitness programs in the market today. What makes Lumosity stand out is its games that mostly focus
on improving one’s memory and problem-solving skills while also working on your attention span.
You can either play the game directly on their website or through their free apps for either iOS or
Android. Lumosity also provides a meditation and mindfulness app called Lumosity Mind. As an
interesting sidenote, studies performed on children with cancer-related brain injuries have shown
developments in memory and executive function after undergoing Lumosity-like brain training.

2. Sudoku
There is nothing wrong with going with a golden oldie and pen and paper favorite like Sudoku. With
no need for fancy graphics nor flashy animations, Sudoku is one of those puzzle games that will get
your brain focused for hours. Sudoku hasn’t lost any of its appeal and it isn’t hard to find a huge
variety of apps to choose from with a countless supply of variations to go with it. Not only does
Sudoku provide brain training, as it relies on short-term memory, it is also a great way of passing
the time and provides you with that added ego-boost every time you complete a puzzle!

3. CogniFit Brain Fitness
Created with the priceless contribution of neuroscientists, this entertaining app is aimed at
improving a user’s levels of memory and concentration. Apart from being able to track your progress
as you go, you can also challenge your friends in an ever-satisfying battle of the brains! What is really
appealing about the app is that it adjusts the difficulty level based on your overall performance and
results. CogniFit Brain Fitness isn’t time consuming and you will start seeing results with a few 20-
to-30-minute sessions per week.

4. Eidetic
Eidetic is a memory enhancement app that uses the repetition technique to aid users in memorizing
important information such as phone numbers, credit card details, passwords or even specific
words. Apart from this Eidetic also notifies you when it is test time, in an attempt to help you retain
information in your long-term memory. Eidetic is a very interesting app for older adults, particularly
those who are beginning to notice memory lapses. Apart from being free, this app is very userfriendly.

5. Braingle
Braingle prides itself in having the largest collection of brain teasers available with over 15,000
puzzles and games. Different from other apps, that focus on memory and reaction-based tests,
Braingle’s approach to help maintain brain sharpness is through the use of riddles, codes and
ciphers, trivia quizzes and optical illusions. You can even play against your friends and family which
adds a lot of interactivity to this already unique product.

6. Personal Zen
Personal Zen’s goal is to reduce stress and increase the user’s well-being. According to the creators,
a 5–10-minute use may improve well-being while a continuous interaction of up to 40 minutes per
week may assist in significantly reducing your stress level. Another very important aspect of this app
is that it trains the brain to focus on positive aspects and provides strategies on keeping out
negativity that can have an unpleasant impact on your mental capabilities.

7. Elevate
Alongside Lumosity, Elevate is widely considered as one of the top 2 brain training apps today. With
over 35 games that track five different types of mental development, it is easy to see why Elevate is
an app to consider. Elevate pays special attention to reading, writing, speaking and math apart from
allowing you to customize your training and focus on whichever subjects you would prefer to pay
more attention to. As with most other brain games, you can track your progress to see how your
skills are improving. The app is free for both iOS and Android.

8. Peak
Peak is an iOS and Android oriented app that looks gorgeous with its very visually pleasing design,
game layout and highly intuitive flow. Peak delivers brain games to work on focus, memory,
problem-solving, mental agility as well as other cognitive functions. Its competitive side is also a plus
as you can challenge other users and are able to compare your progress with Peak’s ever-growing
community. Should you have an Apple Watch, you can seamlessly integrate the app with it. Peak is
free to use and offers a subscription model should you be interested in trying some of its more
advanced features.

9. Crosswords
Alongside Sudoku, Crosswords are a classic brain trainer that combines not only verbal language but
also memory. This is possibly the most recognized form of brain training and surely the one we all
grew up doing, be it printed in the last pages of newspapers, magazines or in dedicated exercise
books. Crossword puzzles are easily found online via free or very cheap apps.

10. Happy Neuron
Happy Neuron splits its games and activities into five important brain areas: memory, attention,
language, executive functions, and visual/spatial, all based on scientific research. As is the case with
other renowned brain training apps, it tailors the training to your personal needs and tracks your
progress. Happy Neuron offers a free trial so you can test their product before purchasing it. The
monthly subscription is well worthwhile, allowing you to access its full content via their site and/or
Android app.

The Smartest People You Have Never Heard of

Posted on November 10, 2020June 26, 2024 by Itamar

Trying to come up with a list of the smartest people who ever stepped foot on the planet is
anything but an easy task to accomplish. Intelligence is highly subjective and so are the skills that
define someone as smart. Being intelligent is one thing, using that intelligence to in some way
advance humanity, is something entirely different. At an IQ level, anything above 140 is generally
considered near genius. Nonetheless, here is a list of some of the brainiest unsung humans who
ever lived.

William Sidis

William James Sidis was an American child prodigy said to have an IQ between 250 and 300,
possibly the highest score ever. Apart from his above-average math skills, which allowed William
to join Harvard at the age of 11, he also spoke 40 languages. Sadly, William did not live up to
expectations and matured into an average human being, landing mediocre jobs and getting into
trouble with the law on several occasions.

Judit Polgár

With an IQ of 170, Judit Polgár was a Hungarian chess player who is widely considered to be the
best female chess player of all time. At the age of 15 years and 4 months, Polgár won the title of
Grandmaster, at the time the youngest to have done so. She is also the youngest person to ever
break into the FIDE top 100 players rating list. She was the top-rated woman in the world from
January 1989 until her retirement on 13 August 2014.

Philip Emeagwali

Philip Emeagwali is a Nigerian computer scientist who won the 1989 Gordon Bell Prize for priceperformance in high-performance computing applications, by using an innovative mathematical
formula and applying it in an oil reservoir modeling calculation. With an IQ of 190, Philip was
voted as the greatest African scientist of all time. As an interesting sidenote, his math work is
often considered as being influential in the construction of the internet.

Srinivasa Ramanujan

Srinivasa Ramanujan was an Indian mathematician who made significant contributions to
analysis, number theory, infinite series and continued fractions, together with solutions to
mathematical problems then deemed unknowable. Ramanujan, who had almost no proper
training in mathematics, initially developed his own research in isolation. His estimated IQ was
185.

Hypatia of Alexandria

Hypatia was a Greek astronomer, philosopher and mathematician who lived in Egypt, then part
of the Eastern Roman Empire. Although heralded by Pandrosion, another Alexandrine female
mathematician, she is the first female mathematician whose life is reasonably well recorded.
With an estimated IQ of 170-190, she was brutally murdered by a group of Christian fanatics
after being accused of witchcraft.

Gottfried Leibniz

Gottfried Wilhelm Leibniz was a renowned German polymath and one of the most significant
logicians, mathematicians and natural philosophers of the Enlightenment and is best known for
inventing calculus. In philosophy, Leibniz is most illustrious for his optimism – his conclusion that
our universe is, in a limited sense, the best possible one that God could have created. Leibniz’s
IQ estimates range from 182 to 205.

Andrew Wiles

Sir Andrew John Wiles is an English mathematician and a Royal Society Research Professor at
the University of Oxford, specialized in number theory. In 1995, Wiles verified a 358-year-old
mathematical theory called Fermat’s Last Theorem, which until then was registered in the
Guinness Book of World Records as the “most difficult math problem” in the world. He was
appointed Knight Commander of the Order of the British Empire in 2000. Sir Andrew Wiles is
said to have an IQ of 170.

Emanuel Swedenborg

Emanuel Swedenborg was a Swedish theologian, scientist, philosopher and mystic. He is best
known for his book on the afterlife, Heaven and Hell. In 1741 he began to experience dreams
and visions which concluded in a “spiritual arising” in which he received a revelation that he was
appointed by Jesus Christ to write The Heavenly Doctrine to reform Christianity.

Christopher Hirata

Christopher Hirata is an American cosmologist and astrophysicist who was hired by NASA at the
age of 16 to do some research on the colonization of Mars. Christopher was only 13 when this
child prodigy won the gold medal in 1996 at the International Physics Olympiad. He also received
his PhD under the supervision of Uroš Seljak in 2005 from Princeton University in Astrophysics.

Kim Ung-Yong

Kim Ung-Yong is a South Korean professor and former child prodigy said to hold the highest IQ
score (210) according to the Guinness World Records. At the age of one, Kim had learned both
the Korean alphabet and 1,000 Chinese characters by studying the Thousand Character Classic,
a 6th-century Chinese poem. At three years old, he began to solve calculus problems. At 5, Kim
had acquired astonishing linguistic skills and could speak Korean, English, French, German and
Japanese.

Ainan Cawley

Ainan Celeste Cawley is a Singaporean boy prodigy who, according to his parents, had said his
first word when he was two weeks old, could walk at six months of age and build difficult
sentences by his first birthday. Cawley gave his first public speech at the age of six and at seven
years and one month of age, he had passed the GCSE chemistry and studied chemistry at the
Singapore Polytechnic a year later. At the age of 9, he was able to recite pi to 518 decimal places
and could remember the periodic table.

Christopher Langan

Christopher Michael Langan is an American autodidact who is considered an intellectual prodigy.
ABC’s 20/20 estimated that Langan’s IQ is anywhere between 195 and 210 dubbing him what
most journalists consider as the smartest man in America. Growing up, Christopher Langan
quickly showed above-average skills: he could speak at six months of age, read by his third
birthday and even question the existence of God by age five. He obtained a perfect score on his
SAT, despite having fallen asleep during the test. He is an avid learner, regardless of the subject,
and can study math, languages and philosophy for long periods of time each day.