Several tests are performed to check one's intellectual activities and maturity. The result of these tests helps to understand one's mental age. If someone's intellectual responses are like a boy of 17 years old, his mental age is considered to be 17 years.

The classic formula to determine IQ score is:

Chronological age is the actual age of the person. However, IQ is tested by modern IQ formulas nowadays. Direct raw scores of the tests are used here to calculate IQ scores. 

The formula is:

x= raw score of the test 

μ= mean raw score of the age group 

σ= standard deviation 

The mean raw score may vary by age but the standard deviation is typically the same in most of the modern tests. This is to make a fair comparison of IQ scores across all age groups.

The average human IQ ranges between 90-109. Half of the population falls under this range value. IQ tests are devised in such a way that the mean average IQ stands at 100. However, not everyone can have an IQ of exactly 100. The score can be deviated from the mean score and obviously, that doesn't indicate anything unusual. About 68% of people's IQ ranges between 85-114 while 50% ranges between 90-109.

Interest in intelligence dates from the very early of civilization. The first idea of testing human intelligence came from Sir Francis Galton in the late 1800s. He was the first to research human intelligence and his paperworks are found to be the first documented works on human intelligence. Galton developed a sensorimotor test that was performed by testing the human's brain response to a given message. Galton's research on human intelligence was a part of the American eugenics movement. However, following on from Galton's research, history was created by Alfred Binet who developed the earliest intelligence test(classic intelligence test) also known as the Binet-Simon test in 1904. Binet was a French Psychologist. At that time, the French Government was trying to figure out a way to identify students with intellectual disability. Mr. Binet and his colleague Simon were a part of that exploration and thus, they developed a standard test in combination with some attention, memory, reasoning and problem-solving-related questions. They prepared a set of questions through which they established a scale of ideal intelligence. The IQ score was checked by dividing an individual's mental age by chronological age and multiplying the result by 100. This formula is the earliest known equation for testing human intelligence.

Types of IQ Tests 

IQ tests are performed in several categories to make the result fair as different people may be good at different categories. The following are the major categories on which the intelligence tests are performed.

• Verbal comprehension 

• Working memory 

• Processing speed 

• Logical-mathematical intelligence 

• Spatial intelligence 

• Language proficiency 

• Reasoning etc.

Several types of tests are popular in the modern day. Each of the tests is designed to measure different aspects of intelligence. Some of the tests are designed for children whereas the rest are for adults. Each test is different from the others. Patterns of questions or designs of the tests can be different in every test. However, all of the tests aim to assess a person's general intelligence. Some popular tests are:

• Stanford-Binet intelligence test 

One of the oldest methods of testing human intelligence. The test measures the following cognitive abilities:

- Fluid reasoning 

- Quantitative reasoning 

- Memory 

- Visual-Spatial

This test is applicable to everyone from children to the elderly.

This is the most popular intelligence testing method used only for adults. This method covers most of the components of intelligence.

Also developed by Weschler to measure the intelligence of children aged from six to sixteen.

This test is applied for children to aged people and covers many of the cognitive skills including:

- Processing speed 

- Memory 

- Language proficiency 

- Mathematical problem-solving ability etc.

This is a non-verbal intelligence test designed to measure fluid intelligence by focusing on tasks like:

- Pattern completion 

- Series completion 

- Matrix 

- Solving puzzles etc.

• Raven's Progressive Matrices 

This test is another non-verbal test that is suitable for children to adults. The test measures abstract reasoning and fluid intelligence by focusing on answering non-verbal questions.

Human intelligence comprises fluid intelligence and crystallized intelligence. Both are different in characteristics. Fluid IQ is related to brain development and functioning and can be defined as reasoning ability, transformation, and flexible thinking which is independent of academic knowledge or experiences. Crystallized intelligence refers to mental skills that are achieved from various life events, verbal ability or social knowledge.

The accuracy of a test depends on many factors like how the test is administered, variation in scoring by test-takers, individual's physical condition, surrounding circumstances etc. However, a well-organized test has a strong correlation with cognitive abilities and can measure the accurate result. It can effectively assess cognitive abilities under ideal circumstances. Several testing organizations are not up to standard which may display unreliable results. To achieve the result with the highest possible accuracy, one can take a controlled, certified and surveilled test in a psychological clinic.

Online tests are controversial in their accuracy in most of the cases. Their ability to measure cognitive intelligence accurately is often questioned. Except few, most of the online platforms do not follow standard strategies to perform a test and that lacks validity of the result. Online tests may only provide you with a general overview of your intelligence but can't perform a comprehensive test. Some limitations of online tests are:

The average IQ score ranges between 90-109. IQ score may vary depending on some factors including age, Country or region, cultural or linguistic background etc. These factors can affect the fairness of the test. A good IQ score set for children is not same for the adults. However, the score of a person should be considered good based on the peer group of people for that person. Generally, teenagers and elderly people have comparatively higher IQ scores. A score above average range can be considered to be a good score. A score over 109 is considered a high average score whereas a score above 130 is a superior one. Only 2% of the population have an IQ score over 130. People with good IQ scores are more organized, creative and disciplined in their day-to-day life. They can think abstractly and logically.

Human intelligence depends on several social and environmental influences. Although most of the human intelligence is genetically inherited, some external factors have strong connections to contribute to intelligence. One can improve his/her cognitive skills by following some brain-boosting activities. Again, the raw IQ score (determined by the standardized tests) remains fairly stable in adulthood. So, early brain development is possibly the best way to boost IQ. A child's IQ can be changed significantly depending on early social and environmental influences. Some guidelines for brain development:-

• Excercise the brain(play brain training games, learn always new, read and think critical and analytical things)

• Consume nutritious and brain-boosting foods(Omega-3 fatty acids, antioxidants, hydrating foods)

• Learn and practice stress management 

• Follow healthy lifestyle(adequate sleep, physical exercise etc.)

• Be self-motivated and practice mindfulness 

Human intelligence changes with age. Several reasons are responsible for the change. Here the intelligence scores for different age groups are shown-

The following figures illustrate average IQ scores for different age ranges. Human intelligence reaches its peak in adolescence period and at the age of 60s or early 70s. The increase during early adulthood is due to proper brain development, along with the growth of cognitive and fluid intelligence. Fluid intelligence generally rises till early adulthood because of better attention control, brain maturation, faster neural connections, adaptive brain functioning etc. However, the fluid intelligence starts to decrease with adulthood but the cognitive intelligence starts rising. The decrease in fluid intelligence may be influenced due to less engagement in academic-style problem-solving as people shift from academic learning to the real world. Life stress, jobs, relationships and finances are some factors that cause a decrease in fluid intelligence in adulthood. However, IQ starts rising in middle age and gradually increases till it hits its peak in late adulthood. The rise of IQ at midlife starts because crystallized intelligence starts becoming stronger, huge life experiences, finance management, better strategic utilization of time and finance, and increased mental discipline which continues to rise till the 60s or early 70s. Logical reasoning, experiences, and socialization are some prominent factors that help elders outperform younger people on IQ scores.

IQ(intelligence quotient) scores notably differ from country to country, region to region. It's important to understand that IQ score isn't the only indicator of a nation's intelligence. However differences may occur because of some factors like-

• Biasness of Tests: IQ tests are mostly based on the Western education system and cultural norms. This may be found as a hindrance for certain populations.

• Educational Access: The structure of the education system in many countries is not the same as in developed countries. So, fluid intelligences are not developed equally to all of the population.

• Socioeconomic Difference: A better socioeconomic structure offers ease of education, a safer environment and abundant resources.

• Genetics: 67% of human intelligence is inherited genetically. Genetics varies in species or population broadly. This may also cause differences in IQ.

A General Overview of higher and lower IQ scores

by country is provided-

There is no strong support found for sex differences in intelligence. However, it is assumed that men have slightly higher cognitive intelligence than female. Cognitive intelligence develops over age. It may maybe influenced by logical reasoning, experiences, socialization, stress management, mental discipline or various other factors. Men often perform better cognitive activities but the difference in cognitive intelligence between men and women remains very small which does not reflect actual intelligence.

IQ stands for intelligence quotient whereas EQ means emotional quotient and both are pretty different from each other. IQ measures one's fluid and cognitive abilities like learning capacity, logic and verbal communication, problem-solving abilities etc. In short, IQ reveals the smartness and intelligence of a person.

On the other side, EQ(emotional quotient) measures one's emotional intelligence by assessing one's ability to understand, use and express their own emotions. Self-motivation, awareness, and empathy are some skills that help one to emotions in a better way.

IQ means intelligence quotient and CQ means cultural quotient, both are not similar. CQ also measures some intellectual activities different from IQ. IQ focuses on verbal & logical intelligence, problem-solving abilities, processing speed etc. CQ is comparatively a new form of intelligence that measures the cultural awareness of a person. It measures metacognitive intelligence, motivational CQ, behavioral CQ etc.

Creativity is the higher potentiality of an individual to provide new solutions to a problem than others or produce something new and useful uniquely and differently. Human intelligence(IQ) is worth mentioning and correlated with creativity. IQ tools(logic, memory, problem-solving ability etc.) help to think and create new. Generally, people with high IQ have a deep ability to think advanced and to combine complex ideas. A high IQ can provide a solid foundation of cognitive skills that may help improve creativity and integrate complex ideas. It is assumed that people with an IQ over 120 have a better knack for creativity. A relative correlation between IQ and creativity is illustrated:-

Human intelligence is not limited to a single particular ability but consists of several distinct modalities. These intelligences are collectively known as multiple Intelligences. Multiple intelligences encompass various types of intelligence and skills beyond just IQ. The following modalities are collectively regarded as Multiple Intelligences:-

• Visual-Spatial 

• Musical rhythmic

• Bodily-kinesthetic

• Verbal-linguistic

• Logical-mathematical

• Naturalistic 

• Intra-personal

• Inter-personal

People having a good combination of multiple intelligences can be privileged in leadership, business and education. IQ score doesn't always disclose the whole story. Multiple Intelligence enables people to unlock their true potential. Multiple Intelligence is not only an alternative to the intelligence quotient but it is the completeness that helps one to succeed with their true potential.

The answer is yes! Low IQ doesn't necessarily mean that one can't figure out or solve problems or can't do better than one with a high IQ. The only difference between a high IQ person with a low IQ person is faster and complex thinking ability. So, it may take a longer or delayed time to solve problems for a person with a low IQ. However, determination, perseverance and focus can lead a person to success. Again, IQ is not the only determinant of success. Emotional intelligence, ethics, skills and training, adaptability, hard work, passion, and motivation are some major factors that influence success. People having these multiple skills and intelligence must be successful.

Perceptions of the public on intelligence testing are not the same anyway. Some may find this irrelevant and dismissive which may develop misconceptions. There are several old and modern intelligence tests. Some modern-day misconceptions are:

• Intelligence is fixed throughout the life.

• IQ test is the only parameter to test intelligence. 

• High IQ is a great achievement. 

• IQ is determined only genetically. 

• IQ is less relevant to EQ.

• IQ is the result of academic education only. 

• High IQ guarantees success. 

• IQ tests are unbiased. 

• People with low IQ will not be successful. 

IQ measures human's cognitive and fluid abilities that allow objective comparison of results. It basically is a parameter to understand a person's intelligence, creativity, problem-solving ability etc. But alongside these, IQ tests are subjected to be criticized in many ways. IQ is not the supreme parameter to determine human creativity, social intelligence or smartness. It completely ignores human emotion, motivation and morality. IQ tests are criticized as:-

• It may often demotivate students by labeling them as slow learners.

• It may give birth to unrealistic expectations.

• It may lower confidence.

• It may underestimate one's potentiality.

• IQ tests may be biased towards one group to another. 

• It may spread a narrow definition of intelligence. 

• It completely underestimates the morality of an individual. 

• People with high IQ may feel fear of failure and may become anxious.