intelligence quotient,

Factors That Affect I.Q.

I made a video based on a review article discussing some factors that influence I.Q. and what I.Q. tests actually measure. Below are links to the videos and a transcript.


IQ which stands for “intelligence quotient” is a score used to quantify a person’s level of intelligence based on standardized tests.

Two popular IQ tests are the Stanford-Binet Intelligence Scale and the Wechsler Adult Intelligence Scale (WAIS)

 The Stanford-Binet Intelligence Scale is a test that is used to detect developmental and mental deficiencies in young children.

This test measures five different factors including

  1. Knowledge
  2. Quantitative reasoning
  3. Visual-spatial processing
  4. Working memory
  5. Fluid reasoning

Some factors contribute to the IQ score more than others.

The Wechsler Adult Intelligence Scale test is used to measure intelligence in adults and adolescents.

The median score is set to 100 and has a standard deviation of 15.

The IQ scores of most people over the age of ten do not change much throughout their lives, but there are some people who score differently when they retake these tests.

In 1921, a researcher by the name of Lewis Terman, started a study known as the Genetic Studies of Genius that tracked the IQ scores of 503 children over time.

 When these children were retested on the Stanford-Binet test during high school their IQs dropped an average of 9 points.

In general, IQ score is affected by a person’s

  1. Specific knowledge
  2. Vocabulary
  3. Expressive language
  4. Memory skills
  5. Visual special abilities
  6. Fine motor coordination
  7. Perceptual skills

Factors that can affect one’s performance on an IQ test include the person’s

  1. Emotional anxiety
  2. Tension
  3. Familiarity with the testing process

In addition, we know that other environmental aspects such as

  1. socioeconomic status
  2. education and
  3. nutrition

are correlated with IQ.


Oommen A (2014) Factors Influencing Intelligence Quotient. J Neurol Stroke 1(4): 00023. DOI: 10.15406/jnsk.2014.01.0002

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.