What is IQ and Which are the most commonly used tests to measure IQ ?

What is IQ

The moment you hear about IQ, the name that comes to your mind is Albert Ensitein. His IQ was around 160 and 190. But it is William James Sidis who holds the record with an IQ score between 250-300. At the age of 11 he presented his study on 4-dimensional physics at Harvard !.

What is IQ

Intelligence Quotient is a measure of a person’s ability to solve complex problems and absorb and memorize new things quickly. It measure’s individual’s intelligence relative to peers of similar age. IQ tests came into existence  in France in the 1900s to identify students who required special assistance in schools. Sir Alfred Binet devised the test initially, which was later modified by David Weschler from US. He included 4 areas of intelligence namely verbal Comprehension Index, a Perceptual Reasoning Index, a Working Memory Index, and a Processing Speed Index.  According to research studies ,modern IQ test is a good predictor of many life outcomes, including educational and career success, health and longevity.

Most commonly used tests for IQ 

  • Stanford-Binet Intelligence Scale: Stanford-Binet test measure intelligence by assessing five factors including fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing and working memory.  Stanford-Binet test is among the most reliable standardized tests currently used in education.


  • Universal Nonverbal Intelligence: This test is designed for children and adolescents (5-17 years). This test measures nonverbal intelligence. This test includes 5 subtests namely Symbolic Memory, Spatial Memory, Object Memory, Cube Design, Analogic Reasoning, and Mazes.

Which are the most commonly used tests to measure IQ


  • Differential Ability Scales: Differential Ability Scales measure cognitive and achievement levels in children for classification and diagnostic purposes.  It consists of 20 subtests, 17 cognitive and 3 achievement subtests yielding an overall cognitive ability score and achievement scores.


  • Peabody Individual Achievement Test: The test is useful in screening children for learning disabilities. It assess the children in following areas namely General Information, Reading Recognition, Reading Comprehension, Mathematics, and Spelling .


  • Wechsler Individual Achievement Test: This tool is good to determine child’s performance in reading, maths, written language and oral language. It helps in determining specific learning disability like Dyslexia. The test takes about 30 to 90 minutes and is used for ages 4 years and above.


  • Wechsler Adult Intelligence Scale : This test is in use from 1955. The test mainly measures Verbal Comprehension, Perceptual Reasoning, Working Memory and Processing Speed. WAIS is the most frequently administered psychological test.


  • Woodcock Johnson III Tests of Cognitive Disabilities: It is useful in assessing cognitive abilities and achievement among children and adults. It is devised based on Cattell-Horn-Carroll (CHC) theory. It is a valuable diagnostic tool to identify exceptional children and high incidence disabilities like head injury, Attention Deficit and Hyperactivity Disorder ADHD.

What does the score mean:

  • Score of 100 : Average
  • Score above 100: High intelligence
  • Score above 150: Super Intelligence
  • Score below 100: below Average
  • Score below 70: Learning disability


Would you like to take the test, Try these links:

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Here are 20 remarkable Brain facts not known by many people

But how much do we know about our own BRAIN : Image

The brain is the crown gem of the human body. It is the seat of intelligence, interpreter of the senses, initiator of body movement, and controller of behavior. The human brain is the most complex organ of the body, and arguably the most complex thing on earth. But how much do we know about our own BRAIN

How many brain cells are in your brain?

The average adult human brain has about 100 billion cells.  It’s still a mystery exactly how these connections work together to create all the marvels of our brains.

Longest living cells in the body

The longest living cells in the body prize goes to brain cells. Most of our brain cells stay  from birth to death. The wiring of these cells changes constantly through our lives.

Water, Water everywhere

Brain is made up of 73% water. 2% dehydration is enough to affect attention, memory and other cognitive skills

Brain feels no PAIN

Brain  do not have any pain receptors. Hence surgeons can perform brain surgery while you are awake. The pain experienced with headache/migraine is because of  the pain receptors present in  layers of coverings, blood vessels, the scalp and some muscles that surrounds the brain.

Brain Loves Cholesterol

Twenty-five percent of the body’s cholesterol resides within the brain. Without proper supply of cholesterol, brain cells die.

Brain is always THINKING

The brain on an average is believed to generate around 50,000 thoughts per day. Sad part is that, in most people 70% of these thoughts are negative. 

Human brain is not SOLID

The human brain is neither solid, nor liquid. It’s soft and squishy similar to the consistency of soft tofu or soft gelatin. And it’s very fragile.

We have a second brain too

The human brain is the most complex organ of the body, and arguably the most complex thing on earth

The brain in your head is not the only brain. There’s a second brain” that lies in intestines that contains around 100 million neurons

Brain generates enough electricity to power a 25-watt light bulb

Read moreHere are 20 remarkable Brain facts not known by many people